This makes a few changes to:
- Make local development consistent with our other apps. It's now
faster to start Celery locally since we don't try to build the
image each time - this is usually quick, but unnecessary.
- Add support for connecting to a local Redis instance. Note that
the previous suggestion of "REDIS = True" was incorrect as this
would be turned into the literal string "True".
I've also co-located and extended the recipes in the Makefile to
make them a bit more visible.