[WIP]Create and show database objects in when running the app

This is a first draft and it's not working, opened the PR just to see changes for future development. 

### TODOs
- [ ] Replace raw mysql ping with a retry mechanism in ruby, example: https://stackoverflow.com/questions/9473957/at-what-point-does-activerecord-actually-connect-to-the-database
- [ ] Use `DATABASE_SERVICE_HOST` instead of hack
does this need to be a ruby script? how about this:

```
ENTRYPOINT ["/tmp/start.sh"]
```

then `start.sh`:

```
#!/bin/bash

# poll for database ready, make it error out after reasonable time
# if ready run migrations/etc
# exec ruby start.app
``

In that case you don't need `%x` or call commands from ruby