Added support for adding/removing custom keynames for distributors at the organization level.
Navigation to orgs from system was broken. Fixed it.
Minor change to test doc string.
Simplify function that checks whether a custom keyname exists in the current page, as well as removing the navigational step.
Changed locator for system's keyname field as per recent changes from https://github.com/Katello/katello/commit/ca3ee86eb6544e5f8cba62065b1196ede37fba1c.
Make sure to check success of keyname creation for datadriven tests.
Merge pull request #697 from omaciel/fixcustominfo

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