Improve Testing

[ckoopmann]

Currently we only have a very basic test for the api that depends on being connected to the dev db.

As the application grows we probably want to extend the testing and build a more robust / reproducible test that run against a specific database state that we control.

Ideas for the db connection issue:

1. Manually spin up a test db and apply migrations to get it into the required state. And then run all tests against that db url.
2. See if there is a way to have more fine grained control over the db state from unit tests etc. (Either by spinning up test dbs from within the test or do some kind of mocking).