Run tests with python setup.py test
Add tox.ini and .travis.yml
Merge pull request #9 from RobrechtDR/master

Restructure and expand tests
Fix tests on Python 3
Add setup.cfg for wheel support
Redundant with the MANIFEST.in entry
Add some entries to the changelog
Fix test cases
Fix snippet

The snippet is supposed to show that the program will count a conditional
path even if would never be triggered. Thanks @sigmavirus24 for spotting the mistake
though.