Merge pull request #20 from joucle/enhancement

Add master key header only if no user session is specified

parse_rest/connection.py

@@ -78,7 +78,8 @@ class ParseBase(object):
         request.add_header('X-Parse-Application-Id', app_id)
         request.add_header('X-Parse-REST-API-Key', rest_key)
 
-        if master_key: request.add_header('X-Parse-Master-Key', master_key)
+        if master_key and 'X-Parse-Session-Token' not in headers.keys():
+            request.add_header('X-Parse-Master-Key', master_key)
 
         request.get_method = lambda: http_verb