[IMP] don't make a temporary copy of dict keys

auditlog/models/rule.py

@@ -39,8 +39,8 @@ class DictDiffer(object):
     """
     def __init__(self, current_dict, past_dict):
         self.current_dict, self.past_dict = current_dict, past_dict
-        self.set_current = set(current_dict.keys())
-        self.set_past = set(past_dict.keys())
+        self.set_current = set(current_dict)
+        self.set_past = set(past_dict)
         self.intersect = self.set_current.intersection(self.set_past)
 
     def added(self):