Adds the PATCH method to extensions

The URLs registered in extensions support methods like
POST, PUT, GET, DELETE but do not support PATCH method.

Added the PATCH method extensions to the supported
method by via "edit" action.

Change-Id: I7f2386010ab01309cf04084a1f9930fcac478d07
Closes-Bug: #1467500

trove/common/extensions.py

@@ -545,6 +545,11 @@ class TroveExtensionMiddleware(ExtensionMiddleware):
             mapper.resource(resource_ext.collection,
                             resource_ext.collection, **kargs)
 
+            mapper.connect(("/%s/{id}" % resource_ext.collection),
+                           controller=controller_resource,
+                           action='edit',
+                           conditions={'method': ['PATCH']})
+
         # extended actions
         action_resources = self._action_ext_resources(application, ext_mgr,
                                                       mapper)