Added management commands to tests

* added --run-once option to the management commands for testing

django_q/management/commands/qcluster.py

@@ -7,7 +7,16 @@ class Command(BaseCommand):
     # Translators: help text for qcluster management command
     help = _("Starts a Django Q Cluster.")
 
+    def add_arguments(self, parser):
+        parser.add_argument('--run-once',
+                            action='store_true',
+                            dest='run_once',
+                            default=False,
+                            help='Run once and then stop.')
+
     def handle(self, *args, **options):
         q = Cluster()
         q.start()
+        if options.get('run_once', False):
+            q.stop()