Add asynchonous loading of movies from OMDB.

Use Celery to run tasks asynchronously. New required setting:
CELERY_BROKER_URL.

Also made the grunt nose task stop on first test failure.

Tests are now run against a fixed-name temp name, to make sure that
the asynchronous tasks re-use the same db as the app that spawned them.
If there's any better solutions to this, please fix.
Make prints py3 compatible.
Merge pull request #2 from streamr/asyncLoad

Async load of movies, check.