Database Support

This is partially a question, possibly a request.

Presumption: This chart doesn't appear to support configuring a database other than H2 (I would be happily wrong, am I missing something?)

Expectation: The helm chart would support configuring Postgres, MySQL, etc. via db.properties, including secrets retrieval for DB credentials, and so on.

Again, unless I'm missing something, is the expectation that users would customize the gocd-server image?

Thanks!