Replace assertItemsEqual with assertCountEqual

assertItemsEqual was removed from Python's unittest.TestCase in
Python 3.3 [1][2]. We have been able to use them since then, because
testtools required unittest2, which still included it. With testtools
removing Python 2.7 support [3][4], we will lose support for
assertItemsEqual, so we should switch to use assertCountEqual.

[1] - https://bugs.python.org/issue17866
[2] - https://hg.python.org/cpython/rev/d9921cb6e3cd
[3] - testing-cabal/testtools#286
[4] - testing-cabal/testtools#277

Change-Id: I9df3355ed619a66d33559366821b907db2950e65

tests/unit/task/scenarios/authenticate/test_authenticate.py

@@ -39,7 +39,7 @@ class AuthenticateTestCase(test.ScenarioTestCase):
         # force glanceclient to actually make the API call, and this
         # results in a bunch of call().__iter__() and call().__len__()
         # calls that aren't matched if we use assert_has_calls().
-        self.assertItemsEqual(
+        self.assertCountEqual(
             self.clients("glance").images.list.call_args_list,
             [mock.call(name=mock.ANY)] * 5)
         self._test_atomic_action_timer(scenario_inst.atomic_actions(),
@@ -88,7 +88,7 @@ class AuthenticateTestCase(test.ScenarioTestCase):
     def test_validate_heat(self):
         scenario_inst = authenticate.ValidateHeat()
         scenario_inst.run(5)
-        self.assertItemsEqual(
+        self.assertCountEqual(
             self.clients("heat").stacks.list.call_args_list,
             [mock.call(limit=0)] * 5)
         self._test_atomic_action_timer(scenario_inst.atomic_actions(),
@@ -97,7 +97,7 @@ class AuthenticateTestCase(test.ScenarioTestCase):
     def test_validate_monasca(self):
         scenario_inst = authenticate.ValidateMonasca()
         scenario_inst.run(5)
-        self.assertItemsEqual(
+        self.assertCountEqual(
             self.clients("monasca").metrics.list.call_args_list,
             [mock.call(limit=0)] * 5)
         self._test_atomic_action_timer(scenario_inst.atomic_actions(),