Speed up functional testing

test/functional/tests.py:TestObjectVersioningUTF8 does not clean
up the versions files it creates because the class's multiple
inheritance is such that it does not call the tearDown method in
TestObjectVersioning.

As a result, any attempt to clean up account containers wastes
time retrying container delete requests. This occurs either in
the setUp for TestSloEnv, if the TestSlo class is included in a
test run, or in the tests.py package tearDown method.

On the author's dev machine this patch reduces the execution
time of functional tests in tests.py by approx 30% or 1 minute.

Change-Id: I8194672bf2ca82435df5868720b6a55a79b94413

test/functional/tests.py

@@ -3359,16 +3359,19 @@ class TestObjectVersioning(Base):
                 "Expected versioning_enabled to be True/False, got %r" %
                 (self.env.versioning_enabled,))
 
-    def tearDown(self):
+    def _tear_down_files(self):
-        super(TestObjectVersioning, self).tearDown()
         try:
-            # only delete files and not container
+            # only delete files and not containers
             # as they were configured in self.env
             self.env.versions_container.delete_files()
             self.env.container.delete_files()
         except ResponseError:
             pass
 
+    def tearDown(self):
+        super(TestObjectVersioning, self).tearDown()
+        self._tear_down_files()
+
     def test_clear_version_option(self):
         # sanity
         self.assertEqual(self.env.container.info()['versions'],
@@ -3602,6 +3605,10 @@ class TestObjectVersioning(Base):
 class TestObjectVersioningUTF8(Base2, TestObjectVersioning):
     set_up = False
 
+    def tearDown(self):
+        self._tear_down_files()
+        super(TestObjectVersioningUTF8, self).tearDown()
+
 
 class TestCrossPolicyObjectVersioning(TestObjectVersioning):
     env = TestCrossPolicyObjectVersioningEnv