Mark the oauth2_provider models as being managed by Django's migrations.
Review Request #1689 — Created July 4, 2019 and updated
Review Board 3.0 shipped with a dependency on a specific version of `oauth2_provider`, which provided some database models. Recent versions of `oauth2_provider` have made updates, through Django's migrations. The current version had migrations as well, but we weren't running a version of Django that used them. This meant that we were missing a bit of migration history, which causes conflicts when Django tries to apply migrations on top of the synced models. This adds some custom evolutions that tells Django Evolution that we want to use migrations for this module, and which migrations would have been applied at the transition point if its models were already synced. Testing Done: Created and upgraded databases successfully against Django 1.11. Reviewed at https://reviews.reviewboard.org/r/10607/