Fix incorrect role assignment in migration.

In the case where a user has existing roles on a project running the
migration would assign those same roles to all the user's projects.

Change-Id: Ibd99bb7cf6cb84b577eca57f903abf9d48e908c1
Fixes: bug 1186128
Live SQL migration tests

Make it possible to run the migration tests for the supported databases
without editing the config files.

Blueprint live-sql-gate

Change-Id: Iaf14ad42333b0a0cd1f7d0fb37f135a8bf7af14a
Merge "Fix incorrect role assignment in migration."
Merge "Live SQL migration tests"