Fixes #4012: Converts sync management and sync schedule routes into reso...

...urces delcarations.

This is needed in order to fix an issue with 3.2.8 and the declaration
of menu's in lib/katello/plugin.rb against Foreman. Rails 3.2.8 is provided
by RHSCL 1.0 and the menu system fails unless a resource for the main
route is delcared via the resources method.