Reorder setup and cleanup functions for readability

As suggested on another patch, reordering these to have the setup
functions together for readability.

Partially-implements bp:resource-cleanup

Change-Id: I8e75d29edc62d30c2ba51f01a3bec490c88adde4

tempest/test.py

@@ -320,20 +320,6 @@ def tearDownClass(cls):
             finally:
                 del trace  # to avoid circular refs
 
-    @classmethod
-    def resource_setup(cls):
-        """Class level resource setup for test cases.
-        """
-        pass
-
-    @classmethod
-    def resource_cleanup(cls):
-        """Class level resource cleanup for test cases.
-        Resource cleanup must be able to handle the case of partially setup
-        resources, in case a failure during `resource_setup` should happen.
-        """
-        pass
-
     @classmethod
     def skip_checks(cls):
         """Class level skip checks. Subclasses verify in here all
@@ -362,6 +348,20 @@ def setup_clients(cls):
         # specify which client is `client` and nothing else.
         pass
 
+    @classmethod
+    def resource_setup(cls):
+        """Class level resource setup for test cases.
+        """
+        pass
+
+    @classmethod
+    def resource_cleanup(cls):
+        """Class level resource cleanup for test cases.
+        Resource cleanup must be able to handle the case of partially setup
+        resources, in case a failure during `resource_setup` should happen.
+        """
+        pass
+
     def setUp(self):
         super(BaseTestCase, self).setUp()
         if not self.setUpClassCalled: