[barbican] Transition Stein to EM

This transition the stein 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: I84b888e3fd63c7c92ace51754ef44af2df31eef4

deliverables/stein/barbican.yaml

@@ -19,6 +19,10 @@ releases:
     projects:
       - repo: openstack/barbican
         hash: 3d23804a6f78f881ac5526bc31e2a7c61b174516
+  - version: stein-em
+    projects:
+      - repo: openstack/barbican
+        hash: 3d23804a6f78f881ac5526bc31e2a7c61b174516
 branches:
   - location: 8.0.0.0rc1
     name: stable/stein

deliverables/stein/python-barbicanclient.yaml

@@ -14,6 +14,10 @@ releases:
       - hash: 1b282358166fe4c1d4dea896bd336b2850584f56
         repo: openstack/python-barbicanclient
     version: 4.8.1
+  - version: stein-em
+    projects:
+      - repo: openstack/python-barbicanclient
+        hash: 1b282358166fe4c1d4dea896bd336b2850584f56
 branches:
   - location: 4.8.1
     name: stable/stein