diff --git a/.travis.yml b/.travis.yml
index b5f5611..e0813ba 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,15 +1,18 @@
 language: python
-python: 2.7
+python: 3.5
 branches:
   only:
   - master
   - /^\d\.\d+$/
   - /^v\d\.\d+\.\d+(rc\d+|dev\d+)?$/
 env:
-- TOXENV=py27
+- TOX_ENV=py27
+- TOX_ENV=py33
+- TOX_ENV=py34
+- TOX_ENV=py35
 install:
 - pip install -U tox twine wheel codecov
-script: tox
+script: tox -e $TOX_ENV
 after_success:
 - codecov
 cache:
diff --git a/docs/conf.py b/docs/conf.py
index cf0d706..a5ca137 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -12,9 +12,7 @@
 # All configuration values have a default; values that are commented out
 # serve to show the default.
 
-import sys
 import os
-import shlex
 from os import path
 from datetime import datetime
 
@@ -26,12 +24,13 @@
 # If extensions (or modules to document with autodoc) are in another directory,
 # add these directories to sys.path here. If the directory is relative to the
 # documentation root, use os.path.abspath to make it absolute, like shown here.
-#sys.path.insert(0, os.path.abspath('.'))
+# import sys
+# sys.path.insert(0, os.path.abspath('.'))
 
 # -- General configuration ------------------------------------------------
 
 # If your documentation needs a minimal Sphinx version, state it here.
-#needs_sphinx = '1.0'
+# needs_sphinx = '1.0'
 
 # Add any Sphinx extension module names here, as strings. They can be
 # extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
@@ -47,7 +46,7 @@
 source_suffix = '.rst'
 
 # The encoding of source files.
-#source_encoding = 'utf-8-sig'
+# source_encoding = 'utf-8-sig'
 
 # The master toctree document.
 master_doc = 'index'
@@ -75,9 +74,9 @@
 
 # There are two options for replacing |today|: either, you set today to some
 # non-false value, then it is used:
-#today = ''
+# today = ''
 # Else, today_fmt is used as the format for a strftime call.
-#today_fmt = '%B %d, %Y'
+# today_fmt = '%B %d, %Y'
 
 # List of patterns, relative to source directory, that match files and
 # directories to ignore when looking for source files.
@@ -85,27 +84,27 @@
 
 # The reST default role (used for this markup: `text`) to use for all
 # documents.
-#default_role = None
+# default_role = None
 
 # If true, '()' will be appended to :func: etc. cross-reference text.
-#add_function_parentheses = True
+# add_function_parentheses = True
 
 # If true, the current module name will be prepended to all description
 # unit titles (such as .. function::).
-#add_module_names = True
+# add_module_names = True
 
 # If true, sectionauthor and moduleauthor directives will be shown in the
 # output. They are ignored by default.
-#show_authors = False
+# show_authors = False
 
 # The name of the Pygments (syntax highlighting) style to use.
 pygments_style = 'sphinx'
 
 # A list of ignored prefixes for module index sorting.
-#modindex_common_prefix = []
+# modindex_common_prefix = []
 
 # If true, keep warnings as "system message" paragraphs in the built documents.
-#keep_warnings = False
+# keep_warnings = False
 
 # If true, `todo` and `todoList` produce output, else they produce nothing.
 todo_include_todos = False
@@ -120,26 +119,26 @@
 # Theme options are theme-specific and customize the look and feel of a theme
 # further.  For a list of options available for each theme, see the
 # documentation.
-#html_theme_options = {}
+# html_theme_options = {}
 
 # Add any paths that contain custom themes here, relative to this directory.
-#html_theme_path = []
+# html_theme_path = []
 
 # The name for this set of Sphinx documents.  If None, it defaults to
 # "<project> v<release> documentation".
-#html_title = None
+# html_title = None
 
 # A shorter title for the navigation bar.  Default is the same as html_title.
-#html_short_title = None
+# html_short_title = None
 
 # The name of an image file (relative to this directory) to place at the top
 # of the sidebar.
-#html_logo = None
+# html_logo = None
 
 # The name of an image file (within the static path) to use as favicon of the
 # docs.  This file should be a Windows icon file (.ico) being 16x16 or 32x32
 # pixels large.
-#html_favicon = None
+# html_favicon = None
 
 # Add any paths that contain custom static files (such as style sheets) here,
 # relative to this directory. They are copied after the builtin static files,
@@ -149,62 +148,62 @@
 # Add any extra paths that contain custom files (such as robots.txt or
 # .htaccess) here, relative to this directory. These files are copied
 # directly to the root of the documentation.
-#html_extra_path = []
+# html_extra_path = []
 
 # If not '', a 'Last updated on:' timestamp is inserted at every page bottom,
 # using the given strftime format.
-#html_last_updated_fmt = '%b %d, %Y'
+# html_last_updated_fmt = '%b %d, %Y'
 
 # If true, SmartyPants will be used to convert quotes and dashes to
 # typographically correct entities.
-#html_use_smartypants = True
+# html_use_smartypants = True
 
 # Custom sidebar templates, maps document names to template names.
-#html_sidebars = {}
+# html_sidebars = {}
 
 # Additional templates that should be rendered to pages, maps page names to
 # template names.
-#html_additional_pages = {}
+# html_additional_pages = {}
 
 # If false, no module index is generated.
-#html_domain_indices = True
+# html_domain_indices = True
 
 # If false, no index is generated.
-#html_use_index = True
+# html_use_index = True
 
 # If true, the index is split into individual pages for each letter.
-#html_split_index = False
+# html_split_index = False
 
 # If true, links to the reST sources are added to the pages.
-#html_show_sourcelink = True
+# html_show_sourcelink = True
 
 # If true, "Created using Sphinx" is shown in the HTML footer. Default is True.
-#html_show_sphinx = True
+# html_show_sphinx = True
 
 # If true, "(C) Copyright ..." is shown in the HTML footer. Default is True.
-#html_show_copyright = True
+# html_show_copyright = True
 
 # If true, an OpenSearch description file will be output, and all pages will
 # contain a <link> tag referring to it.  The value of this option must be the
 # base URL from which the finished HTML is served.
-#html_use_opensearch = ''
+# html_use_opensearch = ''
 
 # This is the file name suffix for HTML files (e.g. ".xhtml").
-#html_file_suffix = None
+# html_file_suffix = None
 
 # Language to be used for generating the HTML full-text search index.
 # Sphinx supports the following languages:
 #   'da', 'de', 'en', 'es', 'fi', 'fr', 'hu', 'it', 'ja'
 #   'nl', 'no', 'pt', 'ro', 'ru', 'sv', 'tr'
-#html_search_language = 'en'
+# html_search_language = 'en'
 
 # A dictionary with options for the search language support, empty by default.
 # Now only 'ja' uses this config value
-#html_search_options = {'type': 'default'}
+# html_search_options = {'type': 'default'}
 
 # The name of a javascript file (relative to the configuration directory) that
 # implements a search results scorer. If empty, the default will be used.
-#html_search_scorer = 'scorer.js'
+# html_search_scorer = 'scorer.js'
 
 # Output file base name for HTML help builder.
 htmlhelp_basename = 'shub-imagedoc'
@@ -212,17 +211,17 @@
 # -- Options for LaTeX output ---------------------------------------------
 
 latex_elements = {
-# The paper size ('letterpaper' or 'a4paper').
-#'papersize': 'letterpaper',
+    # The paper size ('letterpaper' or 'a4paper').
+    # 'papersize': 'letterpaper',
 
-# The font size ('10pt', '11pt' or '12pt').
-#'pointsize': '10pt',
+    # The font size ('10pt', '11pt' or '12pt').
+    # 'pointsize': '10pt',
 
-# Additional stuff for the LaTeX preamble.
-#'preamble': '',
+    # Additional stuff for the LaTeX preamble.
+    # 'preamble': '',
 
-# Latex figure (float) alignment
-#'figure_align': 'htbp',
+    # Latex figure (float) alignment
+    # 'figure_align': 'htbp',
 }
 
 # Grouping the document tree into LaTeX files. List of tuples
@@ -235,23 +234,23 @@
 
 # The name of an image file (relative to this directory) to place at the top of
 # the title page.
-#latex_logo = None
+# latex_logo = None
 
 # For "manual" documents, if this is true, then toplevel headings are parts,
 # not chapters.
-#latex_use_parts = False
+# latex_use_parts = False
 
 # If true, show page references after internal links.
-#latex_show_pagerefs = False
+# latex_show_pagerefs = False
 
 # If true, show URL addresses after external links.
-#latex_show_urls = False
+# latex_show_urls = False
 
 # Documents to append as an appendix to all manuals.
-#latex_appendices = []
+# latex_appendices = []
 
 # If false, no module index is generated.
-#latex_domain_indices = True
+# latex_domain_indices = True
 
 
 # -- Options for manual page output ---------------------------------------
@@ -264,7 +263,7 @@
 ]
 
 # If true, show URL addresses after external links.
-#man_show_urls = False
+# man_show_urls = False
 
 
 # -- Options for Texinfo output -------------------------------------------
@@ -279,19 +278,23 @@
 ]
 
 # Documents to append as an appendix to all manuals.
-#texinfo_appendices = []
+# texinfo_appendices = []
 
 # If false, no module index is generated.
-#texinfo_domain_indices = True
+# texinfo_domain_indices = True
 
 # How to display URL addresses: 'footnote', 'no', or 'inline'.
-#texinfo_show_urls = 'footnote'
+# texinfo_show_urls = 'footnote'
 
 # If true, do not generate a @detailmenu in the "Top" node's menu.
-#texinfo_no_detailmenu = False
+# texinfo_no_detailmenu = False
 
-### Following is taken from https://github.com/snide/sphinx_rtd_theme#using-this-theme-locally-then-building-on-read-the-docs
-# on_rtd is whether we are on readthedocs.org, this line of code grabbed from docs.readthedocs.org
+
+# Following is taken from https://github.com/snide/sphinx_rtd_theme#
+#   using-this-theme-locally-then-building-on-read-the-docs
+
+# on_rtd is whether we are on readthedocs.org,
+# this line of code grabbed from docs.readthedocs.org
 on_rtd = os.environ.get('READTHEDOCS', None) == 'True'
 
 if not on_rtd:  # only import and set the theme if we're building docs locally
@@ -299,5 +302,4 @@
     html_theme = 'sphinx_rtd_theme'
     html_theme_path = [sphinx_rtd_theme.get_html_theme_path()]
 
-# otherwise, readthedocs.org uses their theme by default, so no need to specify it
-### end
+# otherwise, readthedocs.org uses their theme by default, no need to specify it
diff --git a/requirements.in b/requirements.in
index 7819a23..34d6424 100644
--- a/requirements.in
+++ b/requirements.in
@@ -1,5 +1,6 @@
 click
 docker-py
+PyYAML
 requests
 retrying
 shub
diff --git a/requirements.txt b/requirements.txt
index d71e528..84ec6f5 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,18 +1,24 @@
 #
 # This file is autogenerated by pip-compile
-# Make changes in requirements.in, then run this to update:
+# To update, run:
 #
-#    pip-compile requirements.in
+#    pip-compile --output-file requirements.txt requirements.in
 #
-click==6.2
-docker-py==1.7.0
-hubstorage==0.22.0        # via shub
-requests==2.9.1
-retrying==1.3.3           # via hubstorage
-ruamel.base==1.0.0        # via ruamel.yaml
-ruamel.ordereddict==0.4.9  # via ruamel.yaml
-ruamel.yaml==0.10.20      # via shub
+
+backports.ssl-match-hostname==3.5.0.1  # via docker-py
+click==6.6
+docker-py==1.10.6
+docker-pycreds==0.2.1     # via docker-py
+hubstorage==0.23.5        # via shub
+ipaddress==1.0.17         # via docker-py
+PyYAML==3.12              # via shub
+requests==2.10.0
+retrying==1.3.3
 scrapinghub==1.7.0        # via shub
-shub==2.2.0
+shub==2.4.2
 six==1.10.0
-websocket-client==0.35.0  # via docker-py
+websocket-client==0.37.0  # via docker-py
+
+# The following packages are commented out because they are
+# considered to be unsafe in a requirements file:
+# pip                       # via shub
diff --git a/setup.py b/setup.py
index fd12614..b514deb 100644
--- a/setup.py
+++ b/setup.py
@@ -21,7 +21,7 @@
         'requests',
         'six',
         'shub>=0.2.5',
-        'docker-py',
+        'docker-py>=1.10.0',
     ],
     classifiers=[
         'Development Status :: 5 - Production/Stable',
diff --git a/shub_image/build.py b/shub_image/build.py
index 311a69d..eb6b8f4 100644
--- a/shub_image/build.py
+++ b/shub_image/build.py
@@ -1,6 +1,5 @@
 import os
 import re
-import json
 import click
 import warnings
 
@@ -48,8 +47,7 @@ def build_cmd(target, version):
         raise shub_exceptions.BadParameterException(
             'Dockerfile is not found, please use shub-image init cmd')
     is_built = False
-    for line in client.build(path=project_dir, tag=image_name):
-        data = json.loads(line)
+    for data in client.build(path=project_dir, tag=image_name, decode=True):
         if 'stream' in data:
             utils.debug_log("{}".format(data['stream'][:-1]))
             is_built = re.search(
diff --git a/shub_image/check.py b/shub_image/check.py
index 269fd75..db498b6 100644
--- a/shub_image/check.py
+++ b/shub_image/check.py
@@ -1,4 +1,3 @@
-import os
 import click
 import requests
 
diff --git a/shub_image/deploy.py b/shub_image/deploy.py
index f5f773a..d959a71 100644
--- a/shub_image/deploy.py
+++ b/shub_image/deploy.py
@@ -3,12 +3,12 @@
 import ast
 import json
 import time
+import textwrap
+
 import click
 import requests
-import textwrap
-import subprocess
-from urlparse import urljoin
 from retrying import retry
+from six.moves.urllib.parse import urljoin
 
 from shub.deploy import list_targets
 from shub.exceptions import ShubException
@@ -55,11 +55,11 @@
 def cli(target, debug, version, username, password, email,
         apikey, insecure, async):
     deploy_cmd(target, version, username, password, email,
-        apikey, insecure, async)
+               apikey, insecure, async)
 
 
 def deploy_cmd(target, version, username, password, email,
-        apikey, insecure, async):
+               apikey, insecure, async):
     config = utils.load_release_config()
     project, endpoint, target_apikey = config.get_target(target)
     image = config.get_image(target)
diff --git a/shub_image/init.py b/shub_image/init.py
index 603a980..a931713 100644
--- a/shub_image/init.py
+++ b/shub_image/init.py
@@ -1,8 +1,10 @@
 import os
-import click
 import textwrap
 from string import Template
 
+import click
+from six.moves import input
+
 from shub import exceptions as shub_exceptions
 from shub import utils as shub_utils
 from shub_image import utils
@@ -43,7 +45,8 @@
 
 System deps for Dockerfile:
 By default there're several system deps to be included to the Dockerfile ({}),
-you can extend it via --add-deps option, or redefine at all with --base-deps option.
+you can extend it via --add-deps option, or redefine at all with --base-deps
+option.
 
 Python deps for Dockerfile:
 The correct way to install python deps is using requirements.txt. If there's
@@ -104,7 +107,7 @@ def cli(project, base_image, base_deps, add_deps, requirements):
              "no": False, "n": False}
     while True:
         dockefile_path = os.path.join(project_dir, 'Dockerfile')
-        choice = raw_input("Save to {}: (y/n)".format(dockefile_path)).lower()
+        choice = input("Save to {}: (y/n)".format(dockefile_path)).lower()
         if choice in valid:
             if valid[choice]:
                 with open(dockefile_path, 'w') as dockerfile:
diff --git a/shub_image/list.py b/shub_image/list.py
index 0bdddb8..4f39d26 100644
--- a/shub_image/list.py
+++ b/shub_image/list.py
@@ -1,9 +1,8 @@
-import os
-import re
 import json
+
 import click
 import requests
-from urlparse import urljoin
+from six.moves.urllib.parse import urljoin
 
 from shub import exceptions as shub_exceptions
 from shub.deploy import list_targets
diff --git a/shub_image/push.py b/shub_image/push.py
index 797a2ad..c51bee9 100644
--- a/shub_image/push.py
+++ b/shub_image/push.py
@@ -1,4 +1,3 @@
-import json
 import click
 
 from shub.deploy import list_targets
@@ -48,9 +47,8 @@ def push_cmd(target, version, username, password, email, apikey, insecure):
         _execute_push_login(client, image, username, password, email)
     image_name = utils.format_image_name(image, version)
     click.echo("Pushing {} to the registry.".format(image_name))
-    for line in client.push(image_name, stream=True,
+    for data in client.push(image_name, stream=True, decode=True,
                             insecure_registry=not bool(username)):
-        data = json.loads(line)
         if 'status' in data:
             utils.debug_log("Logs:{} {}".format(data['status'],
                             data.get('progress')))
diff --git a/shub_image/tool.py b/shub_image/tool.py
index 6d407fd..742b93d 100644
--- a/shub_image/tool.py
+++ b/shub_image/tool.py
@@ -1,19 +1,6 @@
 import click
 import importlib
 import shub_image
-from shub_image.utils import missing_modules
-
-
-def missingmod_cmd(modules):
-    modlist = ", ".join(modules)
-
-    @click.command(help="*DISABLED* - requires %s" % modlist)
-    @click.pass_context
-    def cmd(ctx):
-        click.echo("Error: '%s' command requires %s" %
-                   (ctx.info_name, modlist))
-        ctx.exit(1)
-    return cmd
 
 
 @click.group(help="Scrapinghub release tool")
@@ -22,22 +9,18 @@ def cli():
     pass
 
 
-module_deps = {
-    "init": [],
-    "build": ["docker"],
-    "list": ["docker"],
-    "test": ["docker"],
-    "push": ["docker"],
-    "deploy": ["docker"],
-    "upload": ["docker"],
-    "check": [],
-}
-
-for command, modules in module_deps.items():
-    m = missing_modules(*modules)
-    if m:
-        cli.add_command(missingmod_cmd(m), command)
-    else:
-        module_path = "shub_image." + command
-        command_module = importlib.import_module(module_path)
-        cli.add_command(command_module.cli, command)
+module_deps = [
+    "init",
+    "build",
+    "list",
+    "test",
+    "push",
+    "deploy",
+    "upload",
+    "check",
+]
+
+for command in module_deps:
+    module_path = "shub_image." + command
+    command_module = importlib.import_module(module_path)
+    cli.add_command(command_module.cli, command)
diff --git a/shub_image/utils.py b/shub_image/utils.py
index 74fd39c..bbc2ac9 100644
--- a/shub_image/utils.py
+++ b/shub_image/utils.py
@@ -1,11 +1,9 @@
 import os
 import re
 import click
-import importlib
 import contextlib
 
-from six import string_types
-import ruamel.yaml as yaml
+import yaml
 
 from shub import config as shub_config
 from shub import utils as shub_utils
@@ -14,7 +12,7 @@
 
 DEFAULT_DOCKER_VERSION = '1.17'
 STATUS_FILE_LOCATION = '.releases'
-_VALIDSPIDERNAME = re.compile('^[a-z0-9][-._a-z0-9]+$', re.I)
+_VALIDSPIDERNAME = re.compile(b'^[a-z0-9][-._a-z0-9]+$', re.I)
 
 DOCKER_UNAVAILABLE_MSG = """
 Detected error connecting to Docker daemon's host.
@@ -83,20 +81,6 @@ def load_release_config():
     return shub_config.load_shub_config()
 
 
-def missing_modules(*modules):
-    """Receives a list of module names and returns those which are missing"""
-    missing = []
-    for module_name in modules:
-        try:
-            importlib.import_module(module_name)
-        except ImportError:
-            if module_name == 'docker':
-                missing.append('docker-py')
-            else:
-                missing.append(module_name)
-    return missing
-
-
 def get_project_dir():
     """ A helper to get project root dir.
         Used by init/build command to locate Dockerfile.
@@ -115,26 +99,13 @@ def get_docker_client(validate=True):
     except ImportError:
         raise ImportError('You need docker-py installed for the cmd')
 
-    class CustomDockerClient(docker.Client):
-
-        # XXX: workaround for https://github.com/docker/docker-py/issues/1059
-        def _stream_helper(self, response, decode=False):
-            it = super(CustomDockerClient, self)._stream_helper(response, decode=decode)
-            for data in it:
-                if not isinstance(data, string_types):
-                    yield data
-                for line in data.split('\r\n'):
-                    line = line.strip()
-                    if line:
-                        yield line
-
     docker_host = os.environ.get('DOCKER_HOST')
     tls_config = None
     if os.environ.get('DOCKER_TLS_VERIFY', False):
         tls_cert_path = os.environ.get('DOCKER_CERT_PATH')
         if not tls_cert_path:
             tls_cert_path = os.path.join(os.path.expanduser('~'), '.docker')
-        apply_path_fun = lambda name: os.path.join(tls_cert_path, name)
+        apply_path_fun = lambda name: os.path.join(tls_cert_path, name)  # noqa
         tls_config = docker.tls.TLSConfig(
             client_cert=(apply_path_fun('cert.pem'),
                          apply_path_fun('key.pem')),
@@ -142,9 +113,9 @@ def _stream_helper(self, response, decode=False):
             assert_hostname=False)
         docker_host = docker_host.replace('tcp://', 'https://')
     version = os.environ.get('DOCKER_VERSION', DEFAULT_DOCKER_VERSION)
-    client = CustomDockerClient(base_url=docker_host,
-                                version=version,
-                                tls=tls_config)
+    client = docker.Client(base_url=docker_host,
+                           version=version,
+                           tls=tls_config)
     if validate:
         validate_connection_with_docker_daemon(client)
     return client
@@ -241,7 +212,7 @@ def _load_status_file(path):
     with open(path, 'r') as f:
         try:
             data = yaml.safe_load(f)
-        except yaml.YAMLError, exc:
+        except yaml.YAMLError as exc:
             raise shub_exceptions.BadConfigException(
                 "Error reading releases file:\n{}".format(exc))
     if not isinstance(data, dict):
diff --git a/tests/test_build.py b/tests/test_build.py
index e96e6c5..69a4c33 100644
--- a/tests/test_build.py
+++ b/tests/test_build.py
@@ -10,14 +10,15 @@
 from .utils import add_fake_dockerfile
 from .utils import add_scrapy_fake_config
 
+
 @mock.patch('shub_image.utils.get_docker_client')
 class TestBuildCli(TestCase):
 
     def test_cli(self, mocked_method):
         mocked = mock.MagicMock()
         mocked.build.return_value = [
-            '{"stream":"all is ok"}',
-            '{"stream":"Successfully built 12345"}']
+            {"stream": "all is ok"},
+            {"stream": "Successfully built 12345"}]
         mocked_method.return_value = mocked
         with FakeProjectDirectory() as tmpdir:
             add_scrapy_fake_config(tmpdir)
@@ -29,14 +30,14 @@ def test_cli(self, mocked_method):
             result = runner.invoke(cli, ["dev", "-d"])
             assert result.exit_code == 0
             mocked.build.assert_called_with(
-                path=tmpdir, tag='registry/user/project:1.0')
+                decode=True, path=tmpdir, tag='registry/user/project:1.0')
             assert os.path.isfile(setup_py_path)
 
     def test_cli_custom_version(self, mocked_method):
         mocked = mock.MagicMock()
         mocked.build.return_value = [
-            '{"stream":"all is ok"}',
-            '{"stream":"Successfully built 12345"}']
+            {"stream": "all is ok"},
+            {"stream": "Successfully built 12345"}]
         mocked_method.return_value = mocked
         with FakeProjectDirectory() as tmpdir:
             add_scrapy_fake_config(tmpdir)
@@ -46,13 +47,13 @@ def test_cli_custom_version(self, mocked_method):
             result = runner.invoke(cli, ["dev", "--version", "test"])
             assert result.exit_code == 0
             mocked.build.assert_called_with(
-                path=tmpdir, tag='registry/user/project:test')
+                decode=True, path=tmpdir, tag='registry/user/project:test')
 
     def test_cli_no_dockerfile(self, mocked_method):
         mocked = mock.MagicMock()
         mocked.build.return_value = [
-            '{"error":"Minor","errorDetail":"Testing output"}',
-            '{"stream":"Successfully built 12345"}']
+            {"error": "Minor", "errorDetail": "Testing output"},
+            {"stream": "Successfully built 12345"}]
         mocked_method.return_value = mocked
         with FakeProjectDirectory() as tmpdir:
             add_scrapy_fake_config(tmpdir)
@@ -64,7 +65,7 @@ def test_cli_no_dockerfile(self, mocked_method):
 
     def test_cli_fail(self, mocked_method):
         mocked = mock.MagicMock()
-        mocked.build.return_value = ['{"error":"Minor","errorDetail":"Test"}']
+        mocked.build.return_value = [{"error": "Minor", "errorDetail": "Test"}]
         mocked_method.return_value = mocked
         with FakeProjectDirectory() as tmpdir:
             add_scrapy_fake_config(tmpdir)
diff --git a/tests/test_check.py b/tests/test_check.py
index d304b9b..14e7721 100644
--- a/tests/test_check.py
+++ b/tests/test_check.py
@@ -1,25 +1,27 @@
-import os
 import mock
 from click.testing import CliRunner
 from unittest import TestCase
 from shub import exceptions as shub_exceptions
+
 from shub_image.check import cli
 from shub_image import utils
-
 from .utils import FakeProjectDirectory
 
+
 class TestCheckCli(TestCase):
 
     @mock.patch('requests.get')
     def test_cli(self, mocked):
-        with FakeProjectDirectory() as tmpdir:
+        # the test creates .releases file locally
+        # this context manager cleans it in the end
+        with FakeProjectDirectory():
             runner = CliRunner()
             result = runner.invoke(cli, [])
             assert result.exit_code == \
                 shub_exceptions.NotFoundException.exit_code
             deploy_id1 = utils.store_status_url('http://linkA', 2)
             deploy_id2 = utils.store_status_url('http://linkB', 2)
-            deploy_id3 = utils.store_status_url('http://linkC', 2)
+            utils.store_status_url('http://linkC', 2)
 
             # get latest (deploy 3)
             result = runner.invoke(cli, [])
diff --git a/tests/test_deploy.py b/tests/test_deploy.py
index 3d4ba67..f44be70 100644
--- a/tests/test_deploy.py
+++ b/tests/test_deploy.py
@@ -1,4 +1,3 @@
-import os
 import mock
 from click.testing import CliRunner
 from unittest import TestCase
diff --git a/tests/test_init.py b/tests/test_init.py
index af7152c..8732e98 100644
--- a/tests/test_init.py
+++ b/tests/test_init.py
@@ -1,7 +1,6 @@
 import os
 from click.testing import CliRunner
 from unittest import TestCase
-from shub import exceptions as shub_exceptions
 
 from shub_image.init import cli
 from shub_image.init import _format_system_deps
@@ -67,11 +66,11 @@ def test_wrap(self):
         assert _wrap(short_cmd) == short_cmd
         assert _wrap(short_cmd + ' ' + short_cmd) == (
             short_cmd + ' ' + ' '.join(short_cmd.split()[:3]) +
-            " \\\n    "  + ' '.join(short_cmd.split()[3:]))
+            " \\\n    " + ' '.join(short_cmd.split()[3:]))
 
     def test_format_system_deps(self):
         # no deps at all
-        assert _format_system_deps('-', None) == None
+        assert _format_system_deps('-', None) is None
         # base deps only
         assert _format_system_deps('a,b,cd', None) == (
             "RUN apt-get update -qq && \\\n"
diff --git a/tests/test_list.py b/tests/test_list.py
index b0f8a1a..1434798 100644
--- a/tests/test_list.py
+++ b/tests/test_list.py
@@ -1,11 +1,9 @@
-import os
 import mock
 from click.testing import CliRunner
 from unittest import TestCase
 
-from shub_image.list import cli, list_cmd
+from shub_image.list import cli
 from shub_image.list import _run_list_cmd
-from shub_image.list import _get_project_settings
 
 from .utils import FakeProjectDirectory
 from .utils import add_sh_fake_config
@@ -14,11 +12,10 @@
 class TestListCli(TestCase):
 
     def test_cli_no_sh_config(self):
-        with FakeProjectDirectory() as tmpdir:
-            runner = CliRunner()
-            result = runner.invoke(cli, ["dev", "-d", "--version", "test"])
-            assert result.exit_code == 69
-            assert 'Could not find image for dev' in result.output
+        runner = CliRunner()
+        result = runner.invoke(cli, ["dev", "-d", "--version", "test"])
+        assert result.exit_code == 69
+        assert 'Could not find image for dev' in result.output
 
     @mock.patch('shub_image.utils.get_docker_client')
     @mock.patch('requests.get')
@@ -26,7 +23,7 @@ def test_cli_no_project(self, get_mocked, get_client_mock):
         client_mock = mock.Mock()
         client_mock.create_container.return_value = {'Id': '1234'}
         client_mock.wait.return_value = 0
-        client_mock.logs.return_value = 'abc\ndef'
+        client_mock.logs.return_value = b'abc\ndef'
         get_client_mock.return_value = client_mock
 
         with FakeProjectDirectory() as tmpdir:
@@ -62,7 +59,7 @@ def test_cli(self, get_mocked, get_client_mock):
         client_mock = mock.Mock()
         client_mock.create_container.return_value = {'Id': '1234'}
         client_mock.wait.return_value = 0
-        client_mock.logs.return_value = 'abc\ndef\ndsd'
+        client_mock.logs.return_value = b'abc\ndef\ndsd'
         get_client_mock.return_value = client_mock
 
         get_settings_mock = mock.Mock()
@@ -83,7 +80,7 @@ def test_cli(self, get_mocked, get_client_mock):
 
 
 class TestListCmd(TestCase):
-    
+
     @mock.patch('shub_image.utils.get_docker_client')
     def test_run_list_cmd(self, get_client_mock):
         client_mock = mock.Mock()
diff --git a/tests/test_push.py b/tests/test_push.py
index e270756..f7a9f52 100644
--- a/tests/test_push.py
+++ b/tests/test_push.py
@@ -1,4 +1,3 @@
-import os
 import mock
 from click.testing import CliRunner
 from unittest import TestCase
@@ -8,6 +7,7 @@
 from .utils import FakeProjectDirectory
 from .utils import add_sh_fake_config
 
+
 @mock.patch('shub_image.utils.get_docker_client')
 class TestPushCli(TestCase):
 
@@ -15,8 +15,8 @@ def test_cli_with_apikey_login(self, mocked_method):
         mocked = mock.MagicMock()
         mocked.login.return_value = {"Status": "Login Succeeded"}
         mocked.push.return_value = [
-            '{"stream":"In process"}',
-            '{"status":"Successfully pushed"}']
+            {"stream": "In process"},
+            {"status": "Successfully pushed"}]
         mocked_method.return_value = mocked
         with FakeProjectDirectory() as tmpdir:
             add_sh_fake_config(tmpdir)
@@ -24,15 +24,15 @@ def test_cli_with_apikey_login(self, mocked_method):
             result = runner.invoke(cli, ["dev", "--version", "test"])
             assert result.exit_code == 0
             mocked.push.assert_called_with(
-                'registry/user/project:test',
+                'registry/user/project:test', decode=True,
                 insecure_registry=False, stream=True)
 
     def test_cli_with_custom_login(self, mocked_method):
         mocked = mock.MagicMock()
         mocked.login.return_value = {"Status": "Login Succeeded"}
         mocked.push.return_value = [
-            '{"stream":"In process"}',
-            '{"status":"Successfully pushed"}']
+            {"stream": "In process"},
+            {"status": "Successfully pushed"}]
         mocked_method.return_value = mocked
         with FakeProjectDirectory() as tmpdir:
             add_sh_fake_config(tmpdir)
@@ -45,15 +45,15 @@ def test_cli_with_custom_login(self, mocked_method):
                 email=u'mail', password=u'pass',
                 reauth=False, registry='registry', username=u'user')
             mocked.push.assert_called_with(
-                'registry/user/project:test',
+                'registry/user/project:test', decode=True,
                 insecure_registry=False, stream=True)
 
     def test_cli_with_insecure_registry(self, mocked_method):
         mocked = mock.MagicMock()
         mocked.login.return_value = {"Status": "Login Succeeded"}
         mocked.push.return_value = [
-            '{"stream":"In process"}',
-            '{"status":"Successfully pushed"}']
+            {"stream": "In process"},
+            {"status": "Successfully pushed"}]
         mocked_method.return_value = mocked
         with FakeProjectDirectory() as tmpdir:
             add_sh_fake_config(tmpdir)
@@ -63,15 +63,15 @@ def test_cli_with_insecure_registry(self, mocked_method):
             assert result.exit_code == 0
             assert not mocked.login.called
             mocked.push.assert_called_with(
-                'registry/user/project:test',
+                'registry/user/project:test', decode=True,
                 insecure_registry=True, stream=True)
 
     def test_cli_with_login_username_only(self, mocked_method):
         mocked = mock.MagicMock()
         mocked.login.return_value = {"Status": "Login Succeeded"}
         mocked.push.return_value = [
-            '{"stream":"In process"}',
-            '{"status":"Successfully pushed"}']
+            {"stream": "In process"},
+            {"status": "Successfully pushed"}]
         mocked_method.return_value = mocked
         with FakeProjectDirectory() as tmpdir:
             add_sh_fake_config(tmpdir)
@@ -83,7 +83,7 @@ def test_cli_with_login_username_only(self, mocked_method):
                 email=None, password=' ',
                 reauth=False, registry='registry', username='apikey')
             mocked.push.assert_called_with(
-                'registry/user/project:test',
+                'registry/user/project:test', decode=True,
                 insecure_registry=False, stream=True)
 
     def test_cli_login_fail(self, mocked_method):
@@ -102,7 +102,7 @@ def test_cli_login_fail(self, mocked_method):
     def test_cli_push_fail(self, mocked_method):
         mocked = mock.MagicMock()
         mocked.login.return_value = {"Status": "Login Succeeded"}
-        mocked.push.return_value = ['{"error":"Failed:(","errorDetail":""}']
+        mocked.push.return_value = [{"error": "Failed:(", "errorDetail": ""}]
         mocked_method.return_value = mocked
         with FakeProjectDirectory() as tmpdir:
             add_sh_fake_config(tmpdir)
diff --git a/tests/test_test.py b/tests/test_test.py
index 8bc9b51..1ebe1bd 100644
--- a/tests/test_test.py
+++ b/tests/test_test.py
@@ -1,8 +1,6 @@
-import os
-import sys
 import mock
+import pytest
 from click.testing import CliRunner
-from unittest import TestCase
 from shub import exceptions as shub_exceptions
 from shub_image.test import cli
 
@@ -19,91 +17,74 @@ class MockedNotFound(Exception):
     """Mocking docker.errors.NotFound"""
 
 
-def _mock_docker_errors_module():
-    """ A helper to avoid using docker library at all"""
-    orig_import = __import__
-    errors_mock = mock.Mock()
-    errors_mock.NotFound = MockedNotFound
-    def import_mock(name, *args):
-        if name == 'docker.errors':
-            return errors_mock
-        return orig_import(name, *args)
-    return import_mock
-
-
-class TestTestCli(TestCase):
-
-    @mock.patch('shub_image.utils.get_docker_client')
-    def test_cli(self, mocked_method):
-        """ This test mocks docker library to test the function itself """
-        client = mock.Mock()
-        # mainly for several checks on status & logs
-        client.create_container.return_value = {'Id': '12345'}
-        client.wait.return_value = 0
-        client.logs.return_value = 'some-logs'
-        mocked_method.return_value = client
-        # patching built-in import to use fake docker.errors
-        import_mock = _mock_docker_errors_module()
-        with mock.patch('__builtin__.__import__', side_effect=import_mock):
-            with FakeProjectDirectory() as tmpdir:
-                add_sh_fake_config(tmpdir)
-                runner = CliRunner()
-                result = runner.invoke(
-                    cli, ["dev", "-d", "--version", "test"])
-                assert result.exit_code == 0
-
-
-class TestTestTools(TestCase):
-
-    def setUp(self):
-        self.client = mock.Mock()
-        self.client.create_container.return_value = {'Id': '12345'}
-        self.client.wait.return_value = 0
-        self.client.logs.return_value = 'some-logs'
-
-    def test_check_image_exists(self):
-        """ This test mocks docker library to test the function itself """
-        # patching built-in import to use fake docker.errors
-        import_mock = _mock_docker_errors_module()
-        with mock.patch('__builtin__.__import__', side_effect=import_mock):
-            assert _check_image_exists('img', self.client) == None
-            self.client.inspect_image.side_effect = MockedNotFound()
-            self.assertRaises(shub_exceptions.NotFoundException,
-                _check_image_exists, 'image', self.client)
-
-    def test_check_sh_entrypoint(self):
-        assert _check_sh_entrypoint('image', self.client) == None
-        self.client.create_container.assert_called_with(
-            image='image',
-            command=['pip', 'show', 'scrapinghub-entrypoint-scrapy'])
-        self.client.wait.return_value = 1
-        self.assertRaises(shub_exceptions.NotFoundException,
-            _check_sh_entrypoint, 'image', self.client)
-        self.client.wait.return_value = 0
-        self.client.logs.return_value = ''
-        self.assertRaises(shub_exceptions.NotFoundException,
-            _check_sh_entrypoint, 'image', self.client)
-
-    def test_start_crawl(self):
-        assert _check_start_crawl_entry('image', self.client) == None
-        self.client.create_container.assert_called_with(
-            image='image', command=['which', 'start-crawl'])
-        self.client.wait.return_value = 1
-        self.assertRaises(shub_exceptions.NotFoundException,
-            _check_start_crawl_entry, 'image', self.client)
-        self.client.wait.return_value = 0
-        self.client.logs.return_value = ''
-        self.assertRaises(shub_exceptions.NotFoundException,
-            _check_start_crawl_entry, 'image', self.client)
-
-    def test_run_docker_command(self):
-        assert _run_docker_command(
-            self.client, 'image-name', ['some', 'cmd']) == \
-                (0, 'some-logs')
-        self.client.create_container.assert_called_with(
-            image='image-name', command=['some', 'cmd'])
-        self.client.start.assert_called_with({'Id': '12345'})
-        self.client.wait.assert_called_with(container='12345')
-        self.client.logs.assert_called_with(
-            container='12345', stdout=True, stderr=False,
-            stream=False, timestamps=False)
+@pytest.fixture
+def docker_client():
+    client = mock.Mock()
+    client.create_container.return_value = {'Id': '12345'}
+    client.wait.return_value = 0
+    client.logs.return_value = 'some-logs'
+    return client
+
+
+def test_test_cli(monkeypatch, docker_client):
+    """ This test mocks docker library to test the function itself """
+    monkeypatch.setattr('docker.errors.NotFound', MockedNotFound)
+    monkeypatch.setattr('shub_image.utils.get_docker_client',
+                        lambda *args, **kwargs: docker_client)
+    with FakeProjectDirectory() as tmpdir:
+        add_sh_fake_config(tmpdir)
+        runner = CliRunner()
+        result = runner.invoke(
+            cli, ["dev", "-d", "--version", "test"])
+        assert result.exit_code == 0
+
+
+def test_check_image_exists(monkeypatch, docker_client):
+    assert _check_image_exists('img', docker_client) is None
+
+    monkeypatch.setattr('docker.errors.NotFound', MockedNotFound)
+    docker_client.inspect_image.side_effect = MockedNotFound
+    with pytest.raises(shub_exceptions.NotFoundException):
+        _check_image_exists('image', docker_client)
+
+
+def test_check_sh_entrypoint(docker_client):
+    assert _check_sh_entrypoint('image', docker_client) is None
+    docker_client.create_container.assert_called_with(
+        image='image',
+        command=['pip', 'show', 'scrapinghub-entrypoint-scrapy'])
+    docker_client.wait.return_value = 1
+    with pytest.raises(shub_exceptions.NotFoundException):
+        _check_sh_entrypoint('image', docker_client)
+
+    docker_client.wait.return_value = 0
+    docker_client.logs.return_value = ''
+    with pytest.raises(shub_exceptions.NotFoundException):
+        _check_sh_entrypoint('image', docker_client)
+
+
+def test_start_crawl(docker_client):
+    assert _check_start_crawl_entry('image', docker_client) is None
+    docker_client.create_container.assert_called_with(
+        image='image', command=['which', 'start-crawl'])
+    docker_client.wait.return_value = 1
+    with pytest.raises(shub_exceptions.NotFoundException):
+        _check_start_crawl_entry('image', docker_client)
+
+    docker_client.wait.return_value = 0
+    docker_client.logs.return_value = ''
+    with pytest.raises(shub_exceptions.NotFoundException):
+        _check_start_crawl_entry('image', docker_client)
+
+
+def test_run_docker_command(docker_client):
+    assert _run_docker_command(
+        docker_client, 'image-name', ['some', 'cmd']) == \
+            (0, 'some-logs')
+    docker_client.create_container.assert_called_with(
+        image='image-name', command=['some', 'cmd'])
+    docker_client.start.assert_called_with({'Id': '12345'})
+    docker_client.wait.assert_called_with(container='12345')
+    docker_client.logs.assert_called_with(
+        container='12345', stdout=True, stderr=False,
+        stream=False, timestamps=False)
diff --git a/tests/test_upload.py b/tests/test_upload.py
index a44d9ff..0ae7aed 100644
--- a/tests/test_upload.py
+++ b/tests/test_upload.py
@@ -1,11 +1,8 @@
-import os
 import mock
 from click.testing import CliRunner
 from unittest import TestCase
 from shub_image.upload import cli
 
-from .utils import FakeProjectDirectory
-from .utils import add_sh_fake_config
 
 class TestUploadCli(TestCase):
 
diff --git a/tests/test_utils.py b/tests/test_utils.py
index 18c3878..a9ecb93 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -1,17 +1,14 @@
 import os
 import sys
-import json
 import tempfile
+from six import StringIO
 from unittest import TestCase
 
 import mock
 import click
-import docker
 import pytest
-import StringIO
 from shub import exceptions as shub_exceptions
 
-from shub_image.utils import missing_modules
 from shub_image.utils import get_project_dir
 from shub_image.utils import get_docker_client
 from shub_image.utils import format_image_name
@@ -29,13 +26,6 @@
 
 class ReleaseUtilsTest(TestCase):
 
-    def test_missing_modules(self):
-        assert missing_modules() == []
-        assert missing_modules('os', 'non-existing-module') == \
-            ['non-existing-module']
-        assert missing_modules('os', 'six', 'xxx11', 'xxx22') == \
-            ['xxx11', 'xxx22']
-
     def test_get_project_dir(self):
         self.assertRaises(
             shub_exceptions.BadConfigException, get_project_dir)
@@ -96,21 +86,6 @@ def test_format_image_name(self):
             mocked.return_value = config
             assert format_image_name('test', None) == 'test:test-version'
 
-    def test_custom_docker_client_workaround(self):
-        """Test workaround for https://github.com/docker/docker-py/issues/1059."""
-        line = (
-            '{"status":"Pulling from library/python","id":"2.7"}\r\n'
-            '{"status":"Pulling fs layer","progressDetail":{},"id":"5c90d4a2d1a8"}\r\n'
-        )
-
-        # mocked_docker.Client._stream_helper.return_value = (line,)
-        client = get_docker_client(validate=False)
-        with mock.patch.object(docker.Client, '_stream_helper', return_value=(line,)):
-            result = list(client._stream_helper(mock.Mock(), decode=False))
-        assert len(result) == 2
-        assert json.loads(result[0])['id'] == '2.7'
-        assert json.loads(result[1])['id'] == '5c90d4a2d1a8'
-
     def test_get_credentials(self):
         assert get_credentials(insecure=True) == (None, None)
         assert get_credentials(apikey='apikey') == ('apikey', ' ')
@@ -130,7 +105,7 @@ def test_init(self):
 
     def test_load(self):
         config = ReleaseConfig()
-        stream = StringIO.StringIO(
+        stream = StringIO(
             'projects:\n  dev: 123\n  prod: 321\n'
             'images:\n  dev: registry/user/project\n  prod: user/project\n'
             'endpoints:\n  dev: http://127.0.0.1/api/scrapyd/\n'
diff --git a/tests/utils.py b/tests/utils.py
index c723fee..10a2e2c 100644
--- a/tests/utils.py
+++ b/tests/utils.py
@@ -37,6 +37,7 @@ def FakeProjectDirectory():
         os.chdir(current)
         shutil.rmtree(tmpdir)
 
+
 def add_scrapy_fake_config(tmpdir):
     # add fake scrapy.cfg
     config_path = os.path.join(tmpdir, 'scrapy.cfg')
diff --git a/tox.ini b/tox.ini
index db597a2..a51e16b 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,13 +1,16 @@
 # tox.ini
 [tox]
-envlist = py27
+envlist = py27,py33,py34,py35
 
 [testenv]
 deps =
     -rrequirements.txt
     mock
+    flake8
     pytest
+    pytest-cov
     Scrapy==1.0.5
 install_command=pip install --process-dependency-links {opts} {packages}
 commands =
-    py.test
+    flake8
+    py.test --cov=shub_image --cov-report= {posargs:shub_image tests}