Merge pull request #746 from karol-brejna-i/745_default-request-handlers

Introduce **kwargs to request_success/failure parameter list

locust/stats.py

@@ -554,10 +554,10 @@ def median_from_dict(total, count):
 A global instance for holding the statistics. Should be removed eventually.
 """
 
-def on_request_success(request_type, name, response_time, response_length):
+def on_request_success(request_type, name, response_time, response_length, **kwargs):
     global_stats.log_request(request_type, name, response_time, response_length)
 
-def on_request_failure(request_type, name, response_time, exception):
+def on_request_failure(request_type, name, response_time, exception, **kwargs):
     global_stats.log_error(request_type, name, exception)
 
 def on_report_to_master(client_id, data):