Report github not drupal

### Acceptance test:

- [x] Install 7.x-1.x or 7.x-1.5
- [x] Go to ``/admin/reports/status`` profile should read: ``DKAN (dkan-)``
- [x] Go to ``/admin/reports/updates/update`` DKAN version should not be correct and links should point to drupal.org for download and updates

- [x] Pull this branch
- [x] Go to ``/admin/reports/status`` profile should read: ``DKAN (dkan-7.x-1.x)``
- [x] Go to ``/admin/reports/updates/update`` DKAN version should be correct and links should point to github for download and updates