PR for factories

Since we are using `CommentFactory` from `factories.py` in production, I made sure that it returns random correct data. Tests are all passing.
Well, tests are part of the code. If I want to update the tests somehow in my codebase, after I've installed your package with some-kind of configuration management tool, I need the version number to be updated. Else, you are forcing me to uninstall and install again the package on all my machines.