Speed up message expiration tests

Speed up the message expiration tests by checking the mongo gc more
often instead of sleeping 60 seconds by default. This also allows using
the ttlMonitorSleepSecs in mongo to reduce the gc interval.

Change-Id: I6f83a76181204f14711a426037dde231ffe97e95

zaqar/tests/unit/storage/base.py

@@ -583,15 +583,20 @@ class MessageControllerTest(ControllerBaseTest):
                                                       client_uuid=client_uuid)
 
         # NOTE(kgriffs): Allow for automatic GC of claims, messages
-        time.sleep(self.gc_interval)
+        for i in range(self.gc_interval):
+            time.sleep(1)
 
             # NOTE(kgriffs): Some drivers require a manual GC to be
             # triggered to clean up claims and messages.
             self.driver.gc()
 
-        with testing.expect(errors.DoesNotExist):
+            try:
                 self.controller.get(self.queue_name, msgid_expired,
                                     project=self.project)
+            except errors.DoesNotExist:
+                break
+        else:
+            self.fail("Didn't remove the queue")
 
         stats = self.queue_controller.stats(self.queue_name,
                                             project=self.project)