Replace global Conf mangling with monkeypatch

The test suite, especially for the brokers, was heavily dependant on the
success of the tests preceeding it to pass. This commit should eliminate
that dependency and allow tests to fail without affecting others.
It also removes the need to cleanup globals manually after a test.

django_q/tests/test_cluster.py

@@ -29,13 +29,8 @@ class WordClass(object):
 
 
 @pytest.fixture
-def broker():
-    Conf.DISQUE_NODES = None
-    Conf.IRON_MQ = None
-    Conf.SQS = None
-    Conf.ORM = None
-    Conf.MONGO = None
-    Conf.DJANGO_REDIS = 'default'
+def broker(monkeypatch):
+    monkeypatch.setattr(Conf, 'DJANGO_REDIS', 'default')
     return get_broker()
 
 
@@ -281,7 +276,7 @@ def test_timeout_override(broker):
 
 
 @pytest.mark.django_db
-def test_recycle(broker):
+def test_recycle(broker, monkeypatch):
     # set up the Sentinel
     broker.list_key = 'test_recycle_test:q'
     async('django_q.tests.tasks.multiply', 2, 2, broker=broker)
@@ -290,8 +285,8 @@ def test_recycle(broker):
     start_event = Event()
     stop_event = Event()
     # override settings
-    Conf.RECYCLE = 2
-    Conf.WORKERS = 1
+    monkeypatch.setattr(Conf, 'RECYCLE', 2)
+    monkeypatch.setattr(Conf, 'WORKERS', 1)
     # set a timer to stop the Sentinel
     threading.Timer(3, stop_event.set).start()
     s = Sentinel(stop_event, start_event, broker=broker)
@@ -310,7 +305,7 @@ def test_recycle(broker):
     # check if the work has been done
     assert result_queue.qsize() == 2
     # save_limit test
-    Conf.SAVE_LIMIT = 1
+    monkeypatch.setattr(Conf, 'SAVE_LIMIT', 1)
     result_queue.put('STOP')
     # run monitor
     monitor(result_queue)
@@ -361,14 +356,14 @@ def test_update_failed(broker):
     sleep(0.5)
     # second save - no success
     old_stopped = task['stopped']
-    task['stopped']=timezone.now()
+    task['stopped'] = timezone.now()
     save_task(task, broker)
     saved_task = Task.objects.get(id=task['id'])
     assert saved_task.stopped > old_stopped
     # third save - success
-    task['stopped']=timezone.now()
-    task['result']='result'
-    task['success']=True
+    task['stopped'] = timezone.now()
+    task['result'] = 'result'
+    task['success'] = True
     save_task(task, broker)
     saved_task = Task.objects.get(id=task['id'])
     assert saved_task.success is True
@@ -383,9 +378,6 @@ def test_update_failed(broker):
     assert saved_task.result == 'result'
 
 
-
-
-
 @pytest.mark.django_db
 def assert_result(task):
     assert task is not None