Mark a whole slew of APIs as internal only.

endpoints/api/user.py

@@ -174,6 +174,7 @@ class User(ApiResource):
       raise request_error(exception=ex)
 
 @resource('/v1/user/private')
+@internal_only
 class PrivateRepositories(ApiResource):
   """ Operations dealing with the available count of private repositories. """
   @require_user_admin