Code review comment for lp:~allenap/maas/cluster-worker-logging

Thanks for the review!

> 3) Using separate task_loggers for each module: What is the purpose
> behind this? If you have a reason, good enough.

This started out as another approach at the problem. I realised it
wasn't the right approach, but decided to leave the change because I
think it adheres closer to Celery's recommended practice (and, indeed,
standard Python use of the logging module).