Adding tox.ini file for tox support and rearranging requirements file to allow testing with multiple Django versions.
Adding multiple python and django version combinations to the travis configuration. That should improve the testing process quite a bit.
Adding documentation on how to run tests with tox.
Disable tests for Python 3 and above since some dependencies don't support Python 3 yet.
Fixing the code base for other python versions like pypy that don't have the exact same ImportError messages as Python 2.7.