Add missing TestCase base.

Author: Fizzadar

tests/test_api/test_api_operations.py

@@ -32,7 +32,7 @@
 from ..util import FakeState, make_inventory
 
 
-class TestOperationMeta():
+class TestOperationMeta(TestCase):
     def test_get_operation_names(self):
         assert len(get_operation_names()) > 0