Refactor

@guilhem: I've added a few commits to the work you have done:

- Removed gem as the default
- Switched back to managed yum repo files directly
- Modified tests to make sure shadowing is working now
- Added you to THANKS file :)
- Version bump

I'm going to release this in a few days, but I wanted you to have a chance to take a look.

Thanks for your work on this!