Add object versioning to QoS DSCP.

- Changes RULE_TYPE_DSCP_MARK to RULE_TYPE_DSCP_MARKING to conform
  with the rules name.
- Added object versioning to qos related objects.
 - qos/rule: Throws a QosRuleVersionUnavailable exception when
   the QosDscpMarkingRule version is < '1.1'.
- removed test object version incrementation TODO from test_policy.py
 - Object versioning can not be used to increment the object version.

Change-Id: I4f10ef3c1cbaa2a868de2b8e3abc4c39eb1f44c7
Partial-Bug: #1468353
diff --git a/neutron/tests/tempest/api/test_qos.py b/neutron/tests/tempest/api/test_qos.py
index 6c6a95a..313715d 100644
--- a/neutron/tests/tempest/api/test_qos.py
+++ b/neutron/tests/tempest/api/test_qos.py
@@ -737,7 +737,7 @@
         policy_rules = retrieved_policy['policy']['rules']
         self.assertEqual(1, len(policy_rules))
         self.assertEqual(rule['id'], policy_rules[0]['id'])
-        self.assertEqual(qos_consts.RULE_TYPE_DSCP_MARK,
+        self.assertEqual(qos_consts.RULE_TYPE_DSCP_MARKING,
                          policy_rules[0]['type'])
 
     @test.idempotent_id('08553ffe-030f-4037-b486-7e0b8fb9385a')