message: Truncate to seconds without using timespec=
  timespec= isn't compatible with Python 3.5.
diff: @@ -279,7 +279,7 @@ def get_upload_path():
  if FLAGS.upload and FLAGS.artifact:
  artifact_filename = os.path.basename(FLAGS.artifact.name)
  ts = datetime.datetime.now(
  - datetime.timezone.utc).isoformat(timespec="seconds")
  + datetime.timezone.utc).replace(microsecond=0).isoformat()
  # note: not os.path.join here, because gsutil is always linux-style
  # Using a timestamp prevents duplicate entries
  path = "{bucket}/{team}/{artifact_id}/{now}.{artifact_filename}".format(
  