Better Healthcheck Testing/Blank database name

[reynoldsalec]

We just implemented a fix to handle situations where the user specifies blank dbname/username for the db config. Ex:

services:
  database:
    type: postgres
      creds:
        user: customusername
        database: customdbname

The fix: 893831a

I put in a "test case" in the custom example to make sure a blank user wouldn't fail the healthcheck or otherwise create problems, however, I'm not testing blank database values. From some quick manual testing it looked like those worked ok, but would be good to explicitly test this.