diff --git a/.travis.yml b/.travis.yml
index f633fe4c..02e096e4 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,14 +1,18 @@
 language: python
 matrix:
   include:
+    - python: 2.7
+      env: TOXENV=py27
+    - python: 3.4
+      env: TOXENV=py34
     - python: 3.5
       env: TOXENV=py35
-env:
-  - TOXENV=py26
-  - TOXENV=py27
-  - TOXENV=py33
-  - TOXENV=py34
-  - TOXENV=pypy
+    - python: 3.6
+      env: TOXENV=py36
+    - python: pypy
+      env: TOXENV=pypy
+    - python: pypy3
+      env: TOXENV=pypy3
 install:
   - travis_retry pip install coveralls tox
 script:
diff --git a/README.rst b/README.rst
index 78639153..be9b1c1f 100644
--- a/README.rst
+++ b/README.rst
@@ -2,7 +2,7 @@ diff-cover |build-status| |coverage-status| |docs-status|
 =========================================================
 
 Automatically find diff lines that need test coverage.
-Also finds diff lines that have violations (according to tools such as pep8,
+Also finds diff lines that have violations (according to tools such as pycodestyle,
 pyflakes, flake8, or pylint).
 This is used as a code quality metric during code reviews.
 
@@ -119,7 +119,7 @@ You can use diff-cover to see quality reports on the diff as well by running
 
     diff-quality --violations=<tool>
 
-Where ``tool`` is the quality checker to use. Currently ``pep8``, ``pyflakes``,
+Where ``tool`` is the quality checker to use. Currently ``pycodestyle``, ``pyflakes``,
 ``flake8``, and ``pylint`` are supported, but more checkers can (and should!)
 be integrated.
 
@@ -129,9 +129,9 @@ Like ``diff-cover``, HTML reports can be generated with
 
     diff-quality --violations=<tool> --html-report report.html
 
-If you have already generated a report using ``pep8``, ``pyflakes``, ``flake8``,
+If you have already generated a report using ``pycodestyle``, ``pyflakes``, ``flake8``,
 or ``pylint`` you can pass the report to ``diff-quality``.  This is more
-efficient than letting ``diff-quality`` re-run ``pep8``, ``pyflakes``,
+efficient than letting ``diff-quality`` re-run ``pycodestyle``, ``pyflakes``,
 ``flake8``, or ``pylint``.
 
 .. code:: bash
@@ -145,15 +145,15 @@ efficient than letting ``diff-quality`` re-run ``pep8``, ``pyflakes``,
     # Use the generated pylint report when running diff-quality
     diff-quality --violations=pylint pylint_report.txt
 
-    # Use a generated pep8 report when running diff-quality.
-    pep8 > pep8_report.txt
-    diff-quality --violations=pep8 pep8_report.txt
+    # Use a generated pycodestyle report when running diff-quality.
+    pycodestyle > pycodestyle_report.txt
+    diff-quality --violations=pycodestyle pycodestyle_report.txt
 
 Note that you must use the ``-f parseable`` option to generate
 the ``pylint`` report for pylint versions less than 1.0 and the
 ``--msg-template`` option for versions >= 1.0.
 
-``diff-quality`` will also accept multiple ``pep8``, ``pyflakes``, ``flake8``,
+``diff-quality`` will also accept multiple ``pycodestyle``, ``pyflakes``, ``flake8``,
 or ``pylint`` reports:
 
 .. code:: bash
@@ -164,7 +164,7 @@ If you need to pass in additional options you can with the ``options`` flag
 
 .. code:: bash
 
-    diff-quality --violations=pep8 --options="--exclude='*/migrations*' --statistics" pep8_report.txt
+    diff-quality --violations=pycodestyle --options="--exclude='*/migrations*' --statistics" pycodestyle_report.txt
 
 Compare Branch
 --------------
@@ -184,7 +184,7 @@ below a certain threshold specify the fail-under parameter
 .. code:: bash
 
     diff-cover coverage.xml --fail-under=80
-    diff-quality --violations=pep8 --fail-under=80
+    diff-quality --violations=pycodestyle --fail-under=80
 
 The above will return a non zero status if the coverage or quality score was below 80%
 
@@ -263,7 +263,7 @@ For example, setting up python 3:
 
     pyvenv venv
     source venv/bin/activate
-    pip install -r test-requirements-py27-py3.txt
+    pip install -r test-requirements.txt
 
 
 Special Thanks
diff --git a/diff_cover/tests/fixtures/empty_pep8_violations.txt b/diff_cover/tests/fixtures/empty_pycodestyle_violations.txt
similarity index 88%
rename from diff_cover/tests/fixtures/empty_pep8_violations.txt
rename to diff_cover/tests/fixtures/empty_pycodestyle_violations.txt
index be36898e..8f266081 100644
--- a/diff_cover/tests/fixtures/empty_pep8_violations.txt
+++ b/diff_cover/tests/fixtures/empty_pycodestyle_violations.txt
@@ -1,6 +1,6 @@
 -------------
 Diff Quality
-Quality Report: pep8
+Quality Report: pycodestyle
 Diff: origin/master...HEAD, staged and unstaged changes
 -------------
 violations_test_file.py (100%)
diff --git a/diff_cover/tests/fixtures/pep8_report.txt b/diff_cover/tests/fixtures/pycodestyle_report.txt
similarity index 100%
rename from diff_cover/tests/fixtures/pep8_report.txt
rename to diff_cover/tests/fixtures/pycodestyle_report.txt
diff --git a/diff_cover/tests/fixtures/pep8_violations_report.html b/diff_cover/tests/fixtures/pycodestyle_violations_report.html
similarity index 99%
rename from diff_cover/tests/fixtures/pep8_violations_report.html
rename to diff_cover/tests/fixtures/pycodestyle_violations_report.html
index 2373ed82..a604e442 100644
--- a/diff_cover/tests/fixtures/pep8_violations_report.html
+++ b/diff_cover/tests/fixtures/pycodestyle_violations_report.html
@@ -76,7 +76,7 @@
     </head>
     <body>
         <h1>Diff Quality</h1>
-        <p>Quality Report: pep8</p>
+        <p>Quality Report: pycodestyle</p>
         <p>Diff: origin/master...HEAD, staged and unstaged changes</p>
         <table border="1">
             <tr>
diff --git a/diff_cover/tests/fixtures/pep8_violations_report.txt b/diff_cover/tests/fixtures/pycodestyle_violations_report.txt
similarity index 92%
rename from diff_cover/tests/fixtures/pep8_violations_report.txt
rename to diff_cover/tests/fixtures/pycodestyle_violations_report.txt
index a8953fc2..f56d703a 100644
--- a/diff_cover/tests/fixtures/pep8_violations_report.txt
+++ b/diff_cover/tests/fixtures/pycodestyle_violations_report.txt
@@ -1,6 +1,6 @@
 -------------
 Diff Quality
-Quality Report: pep8
+Quality Report: pycodestyle
 Diff: origin/master...HEAD, staged and unstaged changes
 -------------
 violations_test_file.py (66.7%):
diff --git a/diff_cover/tests/fixtures/pep8_violations_report_external_css.html b/diff_cover/tests/fixtures/pycodestyle_violations_report_external_css.html
similarity index 98%
rename from diff_cover/tests/fixtures/pep8_violations_report_external_css.html
rename to diff_cover/tests/fixtures/pycodestyle_violations_report_external_css.html
index 02c27af3..14739fc4 100644
--- a/diff_cover/tests/fixtures/pep8_violations_report_external_css.html
+++ b/diff_cover/tests/fixtures/pycodestyle_violations_report_external_css.html
@@ -7,7 +7,7 @@
     </head>
     <body>
         <h1>Diff Quality</h1>
-        <p>Quality Report: pep8</p>
+        <p>Quality Report: pycodestyle</p>
         <p>Diff: origin/master...HEAD, staged and unstaged changes</p>
         <table border="1">
             <tr>
diff --git a/diff_cover/tests/helpers.py b/diff_cover/tests/helpers.py
index 8e1315d2..90b8c542 100644
--- a/diff_cover/tests/helpers.py
+++ b/diff_cover/tests/helpers.py
@@ -2,7 +2,6 @@
 Test helper functions.
 """
 import random
-import sys
 
 import io
 import six
@@ -10,11 +9,6 @@
 import difflib
 from nose.tools import ok_
 
-if sys.version_info[:2] <= (2, 6):
-    import unittest2 as unittest
-else:
-    import unittest
-
 HUNK_BUFFER = 2
 MAX_LINE_LENGTH = 300
 LINE_STRINGS = ['test', '+ has a plus sign', '- has a minus sign']
diff --git a/diff_cover/tests/test_args.py b/diff_cover/tests/test_args.py
index acf9525b..7c4c7216 100644
--- a/diff_cover/tests/test_args.py
+++ b/diff_cover/tests/test_args.py
@@ -1,9 +1,9 @@
 from __future__ import unicode_literals
 import contextlib
 import sys
-from mock import Mock, patch
+from mock import patch
 from diff_cover.tool import parse_coverage_args, parse_quality_args, main
-from diff_cover.tests.helpers import unittest
+import unittest
 
 
 @contextlib.contextmanager
@@ -93,12 +93,12 @@ def test_parse_with_exclude(self):
 class ParseQualityArgsTest(unittest.TestCase):
 
     def test_parse_with_html_report(self):
-        argv = ['--violations', 'pep8',
+        argv = ['--violations', 'pycodestyle',
                 '--html-report', 'diff_cover.html']
 
         arg_dict = parse_quality_args(argv)
 
-        self.assertEqual(arg_dict.get('violations'), 'pep8')
+        self.assertEqual(arg_dict.get('violations'), 'pycodestyle')
         self.assertEqual(arg_dict.get('html_report'), 'diff_cover.html')
         self.assertEqual(arg_dict.get('input_reports'), [])
         self.assertEqual(arg_dict.get('ignore_unstaged'), False)
@@ -131,7 +131,7 @@ def test_parse_with_multiple_input_reports(self):
 
     def test_parse_with_options(self):
         argv = [
-            '--violations', 'pep8',
+            '--violations', 'pycodestyle',
             '--options="--exclude=\'*/migrations*\'"'
         ]
         arg_dict = parse_quality_args(argv)
diff --git a/diff_cover/tests/test_diff_reporter.py b/diff_cover/tests/test_diff_reporter.py
index d158de8a..44f62637 100644
--- a/diff_cover/tests/test_diff_reporter.py
+++ b/diff_cover/tests/test_diff_reporter.py
@@ -1,10 +1,11 @@
 # -*- coding: utf-8 -*-
 from __future__ import unicode_literals
 import mock
+import unittest
 from textwrap import dedent
 from diff_cover.diff_reporter import GitDiffReporter
 from diff_cover.git_diff import GitDiffTool, GitDiffError
-from diff_cover.tests.helpers import line_numbers, git_diff_output, unittest
+from diff_cover.tests.helpers import line_numbers, git_diff_output
 
 
 class GitDiffReporterTest(unittest.TestCase):
diff --git a/diff_cover/tests/test_git_diff.py b/diff_cover/tests/test_git_diff.py
index 56192a8b..813e8685 100644
--- a/diff_cover/tests/test_git_diff.py
+++ b/diff_cover/tests/test_git_diff.py
@@ -2,8 +2,8 @@
 import mock
 
 from diff_cover.command_runner import CommandError
-from diff_cover.git_diff import GitDiffTool, GitDiffError
-from diff_cover.tests.helpers import unittest
+from diff_cover.git_diff import GitDiffTool
+import unittest
 
 
 class TestGitDiffTool(unittest.TestCase):
diff --git a/diff_cover/tests/test_git_path.py b/diff_cover/tests/test_git_path.py
index 1510786b..7389879c 100644
--- a/diff_cover/tests/test_git_path.py
+++ b/diff_cover/tests/test_git_path.py
@@ -1,7 +1,7 @@
 from __future__ import unicode_literals
 import mock
 from diff_cover.git_path import GitPathTool
-from diff_cover.tests.helpers import unittest
+import unittest
 
 
 class TestGitPathTool(unittest.TestCase):
diff --git a/diff_cover/tests/test_integration.py b/diff_cover/tests/test_integration.py
index b9133e27..e5aa5d85 100644
--- a/diff_cover/tests/test_integration.py
+++ b/diff_cover/tests/test_integration.py
@@ -11,7 +11,7 @@
 from collections import defaultdict
 from io import BytesIO
 from subprocess import Popen
-from diff_cover.tests.helpers import unittest
+import unittest
 import io
 import six
 
@@ -382,13 +382,13 @@ def test_git_diff_error_diff_quality(self):
 
         # Expect an error
         with self.assertRaises(CommandError):
-            main(['diff-quality', '--violations', 'pep8'])
+            main(['diff-quality', '--violations', 'pycodestyle'])
 
-    def test_added_file_pep8_html(self):
+    def test_added_file_pycodestyle_html(self):
         self._check_html_report(
             'git_diff_violations.txt',
-            'pep8_violations_report.html',
-            ['diff-quality', '--violations=pep8']
+            'pycodestyle_violations_report.html',
+            ['diff-quality', '--violations=pycodestyle']
         )
 
     def test_added_file_pyflakes_html(self):
@@ -424,24 +424,24 @@ def test_fail_under_pass_html(self):
     def test_html_with_external_css(self):
         temp_dir = self._check_html_report(
             'git_diff_violations.txt',
-            'pep8_violations_report_external_css.html',
-            ['diff-quality', '--violations=pep8'],
+            'pycodestyle_violations_report_external_css.html',
+            ['diff-quality', '--violations=pycodestyle'],
             css_file='external_style.css'
         )
         self.assertTrue(os.path.exists(os.path.join(temp_dir, 'external_style.css')))
 
-    def test_added_file_pep8_console(self):
+    def test_added_file_pycodestyle_console(self):
         self._check_console_report(
             'git_diff_violations.txt',
-            'pep8_violations_report.txt',
-            ['diff-quality', '--violations=pep8']
+            'pycodestyle_violations_report.txt',
+            ['diff-quality', '--violations=pycodestyle']
         )
 
-    def test_added_file_pep8_console_exclude_file(self):
+    def test_added_file_pycodestyle_console_exclude_file(self):
         self._check_console_report(
             'git_diff_violations.txt',
-            'empty_pep8_violations.txt',
-            ['diff-quality', '--violations=pep8', '--options="--exclude=violations_test_file.py"']
+            'empty_pycodestyle_violations.txt',
+            ['diff-quality', '--violations=pycodestyle', '--options="--exclude=violations_test_file.py"']
         )
 
     def test_fail_under_console(self):
@@ -483,14 +483,14 @@ def test_added_file_pylint_console(self):
             ['diff-quality', '--violations=pylint'],
         )
 
-    def test_pre_generated_pep8_report(self):
+    def test_pre_generated_pycodestyle_report(self):
 
-        # Pass in a pre-generated pep8 report instead of letting
-        # the tool call pep8 itself.
+        # Pass in a pre-generated pycodestyle report instead of letting
+        # the tool call pycodestyle itself.
         self._check_console_report(
             'git_diff_violations.txt',
-            'pep8_violations_report.txt',
-            ['diff-quality', '--violations=pep8', 'pep8_report.txt']
+            'pycodestyle_violations_report.txt',
+            ['diff-quality', '--violations=pycodestyle', 'pycodestyle_report.txt']
         )
 
     def test_pre_generated_pyflakes_report(self):
@@ -564,7 +564,7 @@ def test_do_nothing_reporter(self):
         # should not do anything
         # Does demonstrate a reporter can take in any tool
         # name though which is cool
-        reporter = DoNothingDriver('pep8', [], [])
+        reporter = DoNothingDriver('pycodestyle', [], [])
         self.assertEqual(reporter.parse_reports(''), {})
 
 
diff --git a/diff_cover/tests/test_report_generator.py b/diff_cover/tests/test_report_generator.py
index 26d3b69b..7f5263a7 100644
--- a/diff_cover/tests/test_report_generator.py
+++ b/diff_cover/tests/test_report_generator.py
@@ -11,8 +11,9 @@
     StringReportGenerator, TemplateReportGenerator
 )
 from diff_cover.tests.helpers import (
-    load_fixture, assert_long_str_equal, unittest
+    load_fixture, assert_long_str_equal
 )
+import unittest
 from diff_cover.violationsreporters.violations_reporter import BaseViolationReporter, Violation
 
 
diff --git a/diff_cover/tests/test_snippets.py b/diff_cover/tests/test_snippets.py
index 127e8061..d3b34c54 100644
--- a/diff_cover/tests/test_snippets.py
+++ b/diff_cover/tests/test_snippets.py
@@ -7,8 +7,9 @@
 from pygments.token import Token
 from diff_cover.snippets import Snippet
 from diff_cover.tests.helpers import load_fixture,\
-    fixture_path, assert_long_str_equal, unittest
+    fixture_path, assert_long_str_equal
 import six
+import unittest
 
 
 class SnippetTest(unittest.TestCase):
diff --git a/diff_cover/tests/test_violations_reporter.py b/diff_cover/tests/test_violations_reporter.py
index 6bf16b4b..9ac9b654 100644
--- a/diff_cover/tests/test_violations_reporter.py
+++ b/diff_cover/tests/test_violations_reporter.py
@@ -12,10 +12,10 @@
 from diff_cover.violationsreporters import base
 
 from diff_cover.command_runner import CommandError, run_command_for_code
-from diff_cover.tests.helpers import unittest
+import unittest
 from diff_cover.violationsreporters.base import QualityReporter
 from diff_cover.violationsreporters.violations_reporter import (
-    XmlCoverageReporter, Violation, pep8_driver, pyflakes_driver,
+    XmlCoverageReporter, Violation, pycodestyle_driver, pyflakes_driver,
     flake8_driver, PylintDriver, jshint_driver, eslint_driver,
     pydocstyle_driver)
 from mock import Mock, patch, MagicMock
@@ -320,7 +320,7 @@ def _coverage_xml(
         return root
 
 
-class Pep8QualityReporterTest(unittest.TestCase):
+class pycodestyleQualityReporterTest(unittest.TestCase):
 
     def setUp(self):
         _patch_so_all_files_exist()
@@ -333,7 +333,7 @@ def tearDown(self):
 
     def test_quality(self):
 
-        # Patch the output of `pep8`
+        # Patch the output of `pycodestyle`
         _mock_communicate = patch.object(Popen, 'communicate').start()
         return_string = '\n' + dedent("""
                 ../new_file.py:1:17: E231 whitespace
@@ -343,10 +343,10 @@ def test_quality(self):
         _setup_patch((return_string.encode('utf-8'), b''))
 
         # Parse the report
-        quality = QualityReporter(pep8_driver)
+        quality = QualityReporter(pycodestyle_driver)
 
         # Expect that the name is set
-        self.assertEqual(quality.name(), 'pep8')
+        self.assertEqual(quality.name(), 'pycodestyle')
 
         # Measured_lines is undefined for
         # a quality reporter since all lines are measured
@@ -363,46 +363,46 @@ def test_quality(self):
 
     def test_no_quality_issues_newline(self):
 
-        # Patch the output of `pep8`
+        # Patch the output of `pycodestyle`
         _setup_patch((b'\n', b''))
 
         # Parse the report
-        quality = QualityReporter(pep8_driver)
+        quality = QualityReporter(pycodestyle_driver)
         self.assertEqual([], quality.violations('file1.py'))
 
     def test_no_quality_issues_emptystring(self):
 
-        # Patch the output of `pep8`
+        # Patch the output of `pycodestyle`
         _setup_patch((b'', b''))
 
         # Parse the report
-        quality = QualityReporter(pep8_driver)
+        quality = QualityReporter(pycodestyle_driver)
         self.assertEqual([], quality.violations('file1.py'))
 
     def test_quality_error(self):
 
-        # Patch the output of `pep8`
+        # Patch the output of `pycodestyle`
         _setup_patch((b"", 'whoops Ƕئ'.encode('utf-8')), status_code=1)
         with patch('diff_cover.violationsreporters.base.run_command_for_code') as code:
             code.return_value = 0
             # Parse the report
-            quality = QualityReporter(pep8_driver)
+            quality = QualityReporter(pycodestyle_driver)
 
             # Expect that the name is set
-            self.assertEqual(quality.name(), 'pep8')
+            self.assertEqual(quality.name(), 'pycodestyle')
             with self.assertRaises(CommandError) as ex:
                 quality.violations('file1.py')
             self.assertEqual(six.text_type(ex.exception), 'whoops Ƕئ')
 
     def test_no_such_file(self):
-        quality = QualityReporter(pep8_driver)
+        quality = QualityReporter(pycodestyle_driver)
 
         # Expect that we get no results
         result = quality.violations('')
         self.assertEqual(result, [])
 
     def test_no_python_file(self):
-        quality = QualityReporter(pep8_driver)
+        quality = QualityReporter(pycodestyle_driver)
         file_paths = ['file1.coffee', 'subdir/file2.js']
         # Expect that we get no results because no Python files
         for path in file_paths:
@@ -411,9 +411,9 @@ def test_no_python_file(self):
 
     def test_quality_pregenerated_report(self):
 
-        # When the user provides us with a pre-generated pep8 report
-        # then use that instead of calling pep8 directly.
-        pep8_reports = [
+        # When the user provides us with a pre-generated pycodestyle report
+        # then use that instead of calling pycodestyle directly.
+        pycodestyle_reports = [
             BytesIO(('\n' + dedent("""
                 path/to/file.py:1:17: E231 whitespace
                 path/to/file.py:3:13: E225 whitespace
@@ -427,7 +427,7 @@ def test_quality_pregenerated_report(self):
         ]
 
         # Parse the report
-        quality = QualityReporter(pep8_driver, reports=pep8_reports)
+        quality = QualityReporter(pycodestyle_driver, reports=pycodestyle_reports)
 
         # Measured_lines is undefined for
         # a quality reporter since all lines are measured
@@ -1231,8 +1231,8 @@ def test_quality_reporter(self, mock_stderr):
         _patch_so_all_files_exist()
         with patch('diff_cover.violationsreporters.base.run_command_for_code') as code:
             code.return_value = 0
-            reporter = QualityReporter(pep8_driver)
+            reporter = QualityReporter(pycodestyle_driver)
             with self.assertRaises(OSError):
                 reporter.violations("path/to/file.py")
 
-            self.assertEqual(mock_stderr.getvalue(), "pep8 path/to/file.py")
+            self.assertEqual(mock_stderr.getvalue(), "pycodestyle path/to/file.py")
diff --git a/diff_cover/tool.py b/diff_cover/tool.py
index cea52fd0..5828706b 100644
--- a/diff_cover/tool.py
+++ b/diff_cover/tool.py
@@ -22,12 +22,12 @@
 from diff_cover.violationsreporters.base import QualityReporter
 from diff_cover.violationsreporters.violations_reporter import (
     XmlCoverageReporter,
-    flake8_driver, pyflakes_driver, pep8_driver, PylintDriver,
-    jshint_driver, eslint_driver, pydocstyle_driver
-)
+    flake8_driver, pyflakes_driver, PylintDriver,
+    jshint_driver, eslint_driver, pydocstyle_driver,
+    pycodestyle_driver)
 
 QUALITY_DRIVERS = {
-    'pep8': pep8_driver,
+    'pycodestyle': pycodestyle_driver,
     'pyflakes': pyflakes_driver,
     'pylint': PylintDriver(),
     'flake8': flake8_driver,
@@ -139,7 +139,7 @@ def parse_quality_args(argv):
     valid options:
 
         {
-            'violations': pep8 | pyflakes | flake8 | pylint | ...,
+            'violations': pycodestyle| pyflakes | flake8 | pylint | ...,
             'html_report': None | HTML_REPORT,
             'external_css_file': None | CSS_FILE,
         }
diff --git a/diff_cover/violationsreporters/violations_reporter.py b/diff_cover/violationsreporters/violations_reporter.py
index 0a659309..39b341dd 100644
--- a/diff_cover/violationsreporters/violations_reporter.py
+++ b/diff_cover/violationsreporters/violations_reporter.py
@@ -184,12 +184,12 @@ def measured_lines(self, src_path):
         self._cache_file(src_path)
         return self._info_cache[src_path][1]
 
-pep8_driver = RegexBasedDriver(
-    name='pep8',
+pycodestyle_driver = RegexBasedDriver(
+    name='pycodestyle',
     supported_extensions=['py'],
-    command=['pep8'],
+    command=['pycodestyle'],
     expression=r'^([^:]+):(\d+).*([EW]\d{3}.*)$',
-    command_to_check_install=['pep8', '--version']
+    command_to_check_install=['pycodestyle', '--version']
 )
 
 pyflakes_driver = RegexBasedDriver(
@@ -207,10 +207,10 @@ def measured_lines(self, src_path):
     Report Flake8 violations.
 
     Flake8 warning/error codes:
-        E***/W***: pep8 errors and warnings
+        E***/W***: pycodestyle errors and warnings
         F***: pyflakes codes
         C9**: mccabe complexity plugin
-        N8**: pep8-naming plugin
+        N8**: pycodestyle-naming plugin
         T000: flake8-todo plugin
 
     http://flake8.readthedocs.org/en/latest/warnings.html
diff --git a/requirements/test-requirements-py26.txt b/requirements/test-requirements-py26.txt
deleted file mode 100644
index 5fb707bd..00000000
--- a/requirements/test-requirements-py26.txt
+++ /dev/null
@@ -1,4 +0,0 @@
-# Requirements for developing on python 2.6
-astroid<=1.3.2 # rq.filter: >=1.3.2,<1.3.3
-pylint<=1.3.0 # rq.filter: >=1.3,<1.3.1
--r test-requirements.txt
diff --git a/requirements/test-requirements-py27-py3.txt b/requirements/test-requirements-py27-py3.txt
deleted file mode 100644
index 41741769..00000000
--- a/requirements/test-requirements-py27-py3.txt
+++ /dev/null
@@ -1,4 +0,0 @@
-# Requirements for developing on python 2.7 though python 3.4
-pylint
-pydocstyle
--r test-requirements.txt
diff --git a/requirements/test-requirements.txt b/requirements/test-requirements.txt
index 1b5252b7..30316acf 100644
--- a/requirements/test-requirements.txt
+++ b/requirements/test-requirements.txt
@@ -2,7 +2,9 @@
 mock
 nose
 coverage
-pep8
+pycodestyle
 flake8
 pyflakes
+pylint
+pydocstyle
 -r requirements.txt
diff --git a/tox.ini b/tox.ini
index c390ecb7..c8912f0d 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,26 +1,20 @@
 [tox]
-envlist = py26, py27, py33, py34, py35, pypy
+envlist = py27, py34, py35, py36, pypy, pypy3
 
 [testenv]
 whitelist_externals =
     /usr/bin/git
 deps =
-    -r{toxinidir}/requirements/test-requirements-py27-py3.txt
+    -r{toxinidir}/requirements/test-requirements.txt
 commands =
     coverage run -m nose {posargs}
     coverage xml
     git fetch origin master:refs/remotes/origin/master
     diff-cover coverage.xml
-    diff-quality --violation=pep8
+    diff-quality --violation=pycodestyle
     diff-quality --violation=pyflakes
     diff-quality --violation=pylint
 
-[testenv:py26]
-deps =
-    -r{toxinidir}/requirements/test-requirements-py26.txt
-    argparse
-    unittest2
-
 [testenv:py27]
 commands =
     {[testenv]commands}