test_push: add a link to push instructions

BUG=None
TEST=None

Change-Id: Ic23d6e46b24d1776411e7db5c05c876913de6395
Reviewed-on: https://chromium-review.googlesource.com/435038
Commit-Ready: Aviv Keshet <akeshet@chromium.org>
Tested-by: Aviv Keshet <akeshet@chromium.org>
Reviewed-by: Shuqian Zhao <shuqianz@chromium.org>
diff --git a/site_utils/test_push.py b/site_utils/test_push.py
index ff249eb..2118c9e 100755
--- a/site_utils/test_push.py
+++ b/site_utils/test_push.py
@@ -657,7 +657,8 @@
 
     message = ('\nAll tests are completed successfully, the prod branch of the '
                'following repos ready to be pushed to the hash list below.\n'
-               '%s' % updated_repo_msg)
+               '%s\n\n\nInstructions for pushing to prod are available at '
+               'https://goto.google.com/autotest-to-prod' % updated_repo_msg)
     print message
     # Send out email about test completed successfully.
     if arguments.email: