Add QA to test auto devops with DB_INITIALIZE and DB_MIGRATE

What does this MR do?

Add a whole new QA spec to run Auto devops flow to test DB_INITIALIZE and DB_MIGRATE. Possibly with a new rails app

What are the relevant issue numbers?

https://gitlab.com/gitlab-org/gitlab-ce/issues/53314

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• Tests added for this feature/bug
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides

Resources

Eg. https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/22025

https://gitlab.slack.com/archives/C3JJET4Q6/p1538486221000100

use Factory::Repository::ProjectPush.fabricate!