Drop support for Python 3.3 and require at least Python 3.4 (#6).

It is after the end-of-life of Python 3.3 (EOL). See
https://devguide.python.org/#branchstatus

.travis.yml

@@ -1,6 +1,5 @@
 language: python
 python:
-  - 3.3
   - 3.4
   - 3.5
   - 3.6

CHANGELOG.rst

@@ -4,7 +4,10 @@ Changelog
 dev
 ---
 
-* -
+* Dropped support for Python 3.3 as `it is after its end-of-life
+  <https://devguide.python.org/#branchstatus>`_ (`#6
+  <https://github.com/s3rvac/retdec-python/issues/6>`_). The minimal required
+  Python version is now 3.4.
 
 0.5.2 (2017-07-26)
 ------------------

README.rst

@@ -79,7 +79,7 @@ page in the documentation.
 Requirements
 ------------
 
-* Python >= 3.3 (CPython or PyPy)
+* Python >= 3.4 (CPython or PyPy)
 * `requests <http://docs.python-requests.org>`_ module for making HTTPS calls
   to the `retdec.com API <https://retdec.com/api/>`_
 

docs/quickstart.rst

@@ -8,7 +8,7 @@ This page gives an overview of the library and tools to get you started.
 Requirements
 ------------
 
-* Python >= 3.3 (CPython or PyPy)
+* Python >= 3.4 (CPython or PyPy)
 * `requests <http://docs.python-requests.org>`_ module for making HTTPS calls to the `retdec.com API <https://retdec.com/api/>`_
 
 Installation

setup.py

@@ -18,10 +18,10 @@
 # 'encoding' is an invalid keyword argument for this function").
 if sys.version_info[0] == 2:
     sys.exit('Error: retdec-python does not support Python 2. Use Python 3.')
-# Additionally, check that the user runs at least Python 3.3 as this is the
+# Additionally, check that the user runs at least Python 3.4 as this is the
 # minimal required version.
-if sys.version_info < (3, 3):
-    sys.exit('Error: retdec-python requires at least Python 3.3.')
+if sys.version_info < (3, 4):
+    sys.exit('Error: retdec-python requires at least Python 3.4.')
 
 
 # Utility function to read the contents of the given file.
@@ -62,7 +62,6 @@ def get_project_version():
         'License :: OSI Approved :: MIT License',
         'Operating System :: OS Independent',
         'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.3',
         'Programming Language :: Python :: 3.4',
         'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = py33,py34,py35,py36,pypy3
+envlist = py34,py35,py36,pypy3
 
 [testenv]
 deps =