Move url_for into heat_keystoneclient.

This allows faking of this call, and removes one instance of
accessing the encapsulated keystone client.

Change-Id: Iad2a9aaad2e9f1dc3cbeb509c822a61427f12817

heat/common/heat_keystoneclient.py

@@ -151,3 +151,6 @@ class KeystoneClient(object):
     def enable_stack_user(self, user_id):
         # FIXME : This won't work with the v3 keystone API
         self.client.users.update_enabled(user_id, True)
+
+    def url_for(self, **kwargs):
+        return self.client.service_catalog.url_for(**kwargs)

heat/engine/clients.py

@@ -69,7 +69,7 @@ class OpenStackClients(object):
         return self._keystone
 
     def url_for(self, **kwargs):
-        return self.keystone().client.service_catalog.url_for(**kwargs)
+        return self.keystone().url_for(**kwargs)
 
     def nova(self, service_type='compute'):
         if service_type in self._nova:

heat/tests/fakes.py

@@ -133,3 +133,6 @@ class FakeKeystoneClient():
 
     def disable_stack_user(self, user_id):
         pass
+
+    def url_for(self, **kwargs):
+        return 'http://example.com:1234/v1'