This patch addresses the following issues:
1. Running full migration in cockroachdb is quite slow. We already have an approach for unit tests to start from the latest snapshot. This patch makes it possible to use it for integrations tests.
2. Migration requires executing a separated command which makes it hard to run application in containerized test environments (like storj-up) or from IDE. This patch introduces a hidden flag to run migration.
3. Test user creation is painful. We do it with calling GraphQL + admin API. Providing an option with testuser makes the integration tests significant more simple (especially as the projectID -> access grant can be predictable)
Change-Id: I61010728727b490ea6aac32620f2da0484966727
