swarming: add transaction_id to tasks.new request

appengine/swarming/server/task_pack.py

Index: appengine/swarming/server/task_pack.py
diff --git a/appengine/swarming/server/task_pack.py b/appengine/swarming/server/task_pack.py
index ccdc1694745c4e44a28ce2bda8d4a5ef7e2327c5..585b1226a191b5e6082002a179609169b0dd015a 100644
--- a/appengine/swarming/server/task_pack.py
+++ b/appengine/swarming/server/task_pack.py
@@ -78,11 +78,11 @@ def run_result_key_to_performance_stats_key(run_result_key):
 
 
 def get_request_and_result_keys(task_id):
-  """Provides the key and TaskRequest corresponding to a task ID.
+  """Provides request and result keys corresponding to a task ID.
 
   Returns:
     tuple(request_key, result_key): ndb.Key that yield TaskRequest and either
-                                    (TaskRunResult or TaskResultSummay).
+                                    (TaskRunResult or TaskResultSummary).
   """
   try:
     key = unpack_result_summary_key(task_id)