Celery wasn't really being properly connected during tests.

Celery wasn't really being properly connected during tests.

Lots of fixes to do this.

 - setup_celery_from_config no longer responsible for checking
   'celery_setup_elsewhere'; that's the app's job.  (This was a problem
   because more than the app was relying on using this function)
 - Allow us to specifically set the config file we're setting up
   celery from with setup_self
 - Set up celery_always_eager.  This is something we strongly want
   while doing tests.
 - Instead of setting up the app in the get_test_app method, let's set
   that up simply by importing from_tests, which should itself up via
   from_celery being the environment variable being set.