Add simple helper function, to avoid users to learn about the `conn`

stack.

This makes it easier to start using the product.

rq/__init__.py

@@ -1,5 +1,13 @@
+from redis import Redis
 from .proxy import conn
 from .queue import Queue
 from .worker import Worker
 
-__all__ = ['conn', 'Queue', 'Worker']
+def use_redis(redis=None):
+    if redis is None:
+        redis = Redis()
+    elif not isinstance(redis, Redis):
+        raise TypeError('Argument redis should be a Redis instance.')
+    conn.push(redis)
+
+__all__ = ['conn', 'Queue', 'Worker', 'use_redis']