Added support to sync repos via the repository page.

This required tweaking the existing `assert_sync` function at,
ui/sync.py to sync repos via the repository pages.

Added tests to test all the repo types 'yum', 'puppet', 'docker'.
Merge pull request #1635 from kbidarkar/prd-sync-now

Added support to sync repos via the repository page.
Test to associate RH product to activation key
Updated create_cv function to support RH contents as well as custom contents