Comment 6 for bug 1594443

ETA: 24 Jun

RCA: Each cluster's release can be described by a set of requirements that applied to check that everything configured in the right way. However, Nailgun doesn't have versioning to apply actual checks based on cluster's release. Some new features require particular entities in db. Before this problem was solved by adding default values for these particular entities, however, some entities don't have default values. It's hard to foreknow which place will fail during upgrade when the code is being written.