[rabbit] Stop including a default guest account

[streamliner18]

The current implementation bundles a default logging credential for rabbitMQ broker into the docker-compose file. This is extremely insecure as the broker is internet-facing.

Also, there is no flexibility for users to add in their own username and password, as the ConnectionParameters object calls for hostname only.

[streamliner18]

Will also need documentation to instruct users to set up a separate account and delete the default guest user after successful setup.