The "connection: local" option prevented us from running the playbook on
another host (e.g. an app server) which gets around security
restrictions on connecting to DB servers. Also, the option is totally
unnecessary. There's no reason this play couldn't run remotely.

- Delete the create_dbs.yml playbook since we don't use it.
- Update the create_db_and_users.yml playbook to use lists instead of dictionaries.