[storlets] Transition Train to EM

This transition the train branch to extended maintenance.
Changes for bugfixes and things the team deems important are
still encouraged, but there will no longer be official releases
off of the branch.

Please +1 if the team is ready for us to proceed with this
transition, or -1 if there are any final backports currently in
flight that we should wait for. For the latter case, please
update the patch with the new commit hash after doing a final
release to get those changes out so we know to proceed with the
transition.

Change-Id: Ie46c08bcfcb5c1fb61f8e50e7e33b4cac0adffbc

deliverables/train/storlets.yaml

@@ -17,6 +17,10 @@ releases:
       - repo: openstack/storlets
         hash: e107b41ed9c707db67d58f1ada5d1eea1c14e72f
     diff-start: 3.0.0.0rc1
+  - version: train-em
+    projects:
+      - repo: openstack/storlets
+        hash: e107b41ed9c707db67d58f1ada5d1eea1c14e72f
 repository-settings:
   openstack/storlets: {}
 cycle-highlights: