Fixes failing systems tests due to navigation issue and adds distributor test

Systems tests were failing due to 2 issues:

* Navigating to org from a system
* My fix https://github.com/Katello/katello/pull/1975 got reversed by https://github.com/komidore64/katello/commit/3557cf785ecd45c111b5e741c4f65a023d725865 so I submitted another PR: https://github.com/Katello/katello/pull/2223

I ended up adding a test or two for custom distributor information at the Org level. Feel free to review and merge once the above PR is merged.