Make Travis use an ES version we support
Merge pull request #115 from edx/gprice/travis-es-version

Make Travis use an ES version we support
Remove unused endpoints
Allow filtering by group_id in more endpoints

All endpoints that return lists of threads (except the endpoint used by
the notifier component) now allow filtering by group_id and are tested
accordingly.
Number of post are incorrect becuase deletion of comments doesn't perform deletion of subcomments one by one which cause magical comment counter not to decrese the counter properly
TNL-91
Merge pull request #113 from mlkwaqas/waqas/tnl91-incorrect-post-number

Number of post are incorrect
Merge pull request #114 from edx/gprice/test-group-id

Allow filtering by group_id in more endpoints
Add the ability to query multiple group ids