Update outdated sample codes in README.md

* Use explicit connection management instead of `use_connection()`.
* Use `rq worker` instead of `rqworker`.

README.md

@@ -38,9 +38,10 @@ You do use the excellent [requests][r] package, don't you?
 Then, create an RQ queue:
 
 ```python
-from rq import Queue, use_connection
-use_connection()
-q = Queue()
+from redis import Redis
+from rq import Queue
+
+q = Queue(connection=Redis())
 ```
 
 And enqueue the function call: