Fixed typo in sample test command
Add support for using django-redis cache for queues

- Create alternate configuration using REDIS_CACHE to indirectly
  specify that queue Redis settings should mirror cache settings.
- Add test case to confirm correct operation, conditional upon
  django-redis being installed.
- Add documentation of option in README.rst.
Add Alan Johnson to Contributors
Add compatibility with django-redis-cache

- Differentiate between django-redis and django-redis-cache in tests
  and in get_redis_connection account for configuration differences
- Update documentation
Merge pull request #25 from acjohnson55/master

Added support for reusing cache connection from django-redis or django-redis-cache. Fixes #24