Argo workflows's should stick around for a week or so. (kubeflow#363)

* Argo workflows were being GC'd after 3 hours like other resources. That is
too aggressive. We want the workflows to be around longer to aid debugging.
* Fix 362

py/kubeflow/testing/cleanup_ci.py

@@ -80,7 +80,7 @@ def cleanup_workflows(args):
 
     name = w["metadata"]["name"]
     age = now - start_time
-    if age > datetime.timedelta(hours=args.max_age_hours):
+    if age > datetime.timedelta(hours=args.max_wf_age_hours):
       logging.info("Deleting workflow: %s", name)
       is_expired = True
       if not args.dryrun:
@@ -624,6 +624,10 @@ def main():
   parser.add_argument(
     "--max_age_hours", default=3, type=int, help=("The age of deployments to gc."))
 
+  parser.add_argument(
+    "--max_wf_age_hours", default=7*24, type=int,
+    help=("How long to wait before garbage collecting Argo workflows."))
+
   parser.add_argument('--dryrun', dest='dryrun', action='store_true')
   parser.add_argument('--no-dryrun', dest='dryrun', action='store_false')
   parser.set_defaults(dryrun=False)