[tacker] 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: If2fae245eaa507c3f9790d0caa91d477e82689ea

deliverables/stein/python-tackerclient.yaml

@@ -9,6 +9,10 @@ releases:
       - hash: f4839f308ab341bbb4a8faa818b0d6eba2048819
         repo: openstack/python-tackerclient
     version: 0.15.0
+  - version: stein-em
+    projects:
+      - repo: openstack/python-tackerclient
+        hash: f4839f308ab341bbb4a8faa818b0d6eba2048819
 repository-settings:
   openstack/python-tackerclient: {}
 branches:

deliverables/stein/tacker-horizon.yaml

@@ -16,6 +16,10 @@ releases:
     projects:
       - repo: openstack/tacker-horizon
         hash: 471af9fd63ea5152ad7110e8e7717f6260a63ec4
+  - version: stein-em
+    projects:
+      - repo: openstack/tacker-horizon
+        hash: 471af9fd63ea5152ad7110e8e7717f6260a63ec4
 repository-settings:
   openstack/tacker-horizon: {}
 branches:

deliverables/stein/tacker.yaml

@@ -23,6 +23,10 @@ releases:
     projects:
       - repo: openstack/tacker
         hash: aee46c86bbe87cbb8b6ebb3bd9b765aafd13df53
+  - version: stein-em
+    projects:
+      - repo: openstack/tacker
+        hash: aee46c86bbe87cbb8b6ebb3bd9b765aafd13df53
 branches:
   - location: 1.0.0.0rc1
     name: stable/stein