Pass time info trough tmp file

tavern_time_request/request.py

 import logging
 import requests
+import csv
 from tavern.util import exceptions
 from tavern._plugins.rest.request import RestRequest
 from time import perf_counter as perf
+from uuid import uuid4
 
 logger = logging.getLogger(__name__)
 
 class HivemindRequest(RestRequest):
     def run(self):
         try:
-            # add sent timestamp to each request in perf_counter format
             start_time = perf()
-            headers = self._request_args.get('headers', {})
-            headers['Sent-At'] = str(start_time)
-            self._request_args['headers'] = headers
+            test_id = uuid4()
+            with open("/tmp/test_ids.csv", "a") as f:
+                writer = csv.writer(f)
+                writer.writerow([str(test_id), start_time])
+            self._request_args['json']['id'] = str(test_id)
             return self._prepared()
         except requests.exceptions.RequestException as e:
             logger.exception("Error running prepared request")