Comment 0 for bug 1258041

In test_availability_zones.py and and test_compute.py, There are two tests for availability_zones.reset_cache which can not make sense.

Follow code:
        az.reset_cache()
        self.assertIsNone(az._get_cache().get('cache'))

if we do not add cache for key 'cache', the result of az._get_cache().get('cache') before az.reset_cache() is same as after az.reset_cache(). So it can not make sense.