update readme

README.md

@@ -94,10 +94,13 @@ __Returns__: {undefined} returns nothing
 The handler object also emits the following events:
 
 ### handler.on('error', function(err) {...})
-
 If your function returns an error to the callback, this event will be emitted.
 The subscribed function will receive an error as it's only parameter.
 
+### handler.on('stop', function() {...})
+The stop event is emitted when reissue successfully completes any ongoing
+function invocations and stops all future invocations.
+
 
 ## Contributing