Fixes #7233 - Drop Ruby 1.8.7 and revert Ruby 1.8.7 specifics

- [x] rake test passed
- [x] rails server loaded and function correctly
- [x] Ubuntu 12.04 packaging blocker issue 
- [x] drop 1.8.7 tests on Jenkins
Our package is 1.3.1, so this may need reducing.  I think we might be able to file a ticket to remove it altogether, as I think it should have been part of http://projects.theforeman.org/issues/3840 (@ares?).