Passing tests

This PR brings the pulp_python repo into a state of passing unit and flake8 tests.
I used it here just because it is used everywhere else. I think the original reason we made it was that it made it easier to skip tests on EL 5. Admittedly, this plugin may never support EL 5 though I am not sure. I do plan to make consumer functions for it so you can tell a client to pip install things. It's possible that it might work on EL 5.

https://github.com/pulp/pulp/blob/master/devel/pulp/devel/test_runner.py