Use more specific asserts in tests

Instead of assertTrue and assertFalse use more specific asserts.
They are compatible with Python 2.7[1] and 3.4[2]

[1]: https://docs.python.org/2.7/library/unittest.html
[2]: https://docs.python.org/3.4/library/unittest.html

Change-Id: Ifee66714db561fb329911395b2cfdd90c689b609

functional/test_resource_chain.py

@@ -58,7 +58,7 @@ class ResourceChainTests(functional_base.FunctionalTestsBase):
 
         # Verify
         stack = self.client.stacks.get(stack_id)
-        self.assertTrue(stack is not None)
+        self.assertIsNotNone(stack)
 
         # Top-level resource for chain
         expected = {'my-chain': 'OS::Heat::ResourceChain'}
@@ -74,15 +74,15 @@ class ResourceChainTests(functional_base.FunctionalTestsBase):
 
         # Outputs
         resource_ids = self._stack_output(stack, 'resource-ids')
-        self.assertTrue(resource_ids is not None)
+        self.assertIsNotNone(resource_ids)
         self.assertEqual(2, len(resource_ids))
 
         resource_value = self._stack_output(stack, 'resource-0-value')
-        self.assertTrue(resource_value is not None)
+        self.assertIsNotNone(resource_value)
         self.assertEqual(8, len(resource_value))  # from parameter
 
         resource_attrs = self._stack_output(stack, 'all-resource-attrs')
-        self.assertTrue(resource_attrs is not None)
+        self.assertIsNotNone(resource_attrs)
         self.assertIsInstance(resource_attrs, dict)
         self.assertEqual(2, len(resource_attrs))
         self.assertEqual(8, len(resource_attrs['0']))

functional/test_stack_events.py

@@ -74,7 +74,7 @@ outputs:
                 stack_event.resource_name)
 
             # Resource events are a subset of the original stack event list
-            self.assertTrue(len(resource_events) < len(stack_events))
+            self.assertLess(len(resource_events), len(stack_events))
 
             # Get the event details for each resource event
             for resource_event in resource_events:

scenario/test_server_software_config.py

@@ -100,7 +100,7 @@ class SoftwareConfigIntegrationTest(scenario_base.ScenarioTestsBase):
             res1['result'])
         self.assertEqual(0, res1['status_code'])
         self.assertEqual('Output to stderr\n', res1['stderr'])
-        self.assertTrue(len(res1['stdout']) > 0)
+        self.assertGreater(len(res1['stdout']), 0)
 
         res2 = self._stack_output(stack, 'res2')
         self.assertEqual(
@@ -118,7 +118,7 @@ class SoftwareConfigIntegrationTest(scenario_base.ScenarioTestsBase):
             res3['result'])
         self.assertEqual(0, res3['status_code'])
         self.assertEqual('', res3['stderr'])
-        self.assertTrue(len(res1['stdout']) > 0)
+        self.assertGreater(len(res1['stdout']), 0)
 
         dep1_resource = self.client.resources.get(sid, 'dep1')
         dep1_id = dep1_resource.physical_resource_id