Old Jobs Prevent Migrations From Running

[Sovietaced]

I just wanted to report a usability issue we have. We're in the process of upgrading Armada to a new version and the lookout/scheduler migrations never ran because there were old completed jobs on the cluster. It would be could if we could ensure migrations can be run somehow.

[dejanzele]

As mentioned here #348 (comment), I am working on a proposal for a new migrations system.