'get_storage_class raises an error if the requested module don\'t exist.'

def test_get_nonexisting_storage_module(self):

    self.assertRaisesRegexp(ImproperlyConfigured, 'Error    importing    storage    module    django.core.files.non_existing_storage:    "No    module    named    .*non_existing_storage"', get_storage_class, 'django.core.files.non_existing_storage.NonExistingStorage')
