Update the documentation link for doc migration

This patch is proposed according to the Direction 10 of doc
migration(https://etherpad.openstack.org/p/doc-migration-tracking).

Change-Id: I4eb594115e350e28f9136f7003692a1ec0abfcf6

watcher/applier/workflow_engine/default.py

@@ -34,7 +34,7 @@ class DefaultWorkFlowEngine(base.BaseWorkFlowEngine):
     """Taskflow as a workflow engine for Watcher
 
     Full documentation on taskflow at
-    http://docs.openstack.org/developer/taskflow/
+    https://docs.openstack.org/taskflow/latest
     """
 
     def decider(self, history):

watcher/common/policy.py

@@ -49,7 +49,7 @@ def init(policy_file=None, rules=None,
     """
     global _ENFORCER
     if not _ENFORCER:
-        # http://docs.openstack.org/developer/oslo.policy/usage.html
+        # https://docs.openstack.org/oslo.policy/latest/admin/index.html
         _ENFORCER = policy.Enforcer(CONF,
                                     policy_file=policy_file,
                                     rules=rules,

watcher/decision_engine/model/notification/nova.py

@@ -249,7 +249,9 @@ class InstanceCreated(VersionedNotificationEndpoint):
             event_type='instance.update',
             # To be "fully" created, an instance transitions
             # from the 'building' state to the 'active' one.
-            # See http://docs.openstack.org/developer/nova/vmstates.html
+            # See https://docs.openstack.org/nova/latest/reference/
+            # vm-states.html
+
             payload={
                 'nova_object.data': {
                     'state': element.InstanceState.ACTIVE.value,