[tacker] Transition Ussuri to EM

This transition the ussuri 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: I418baea7bb00ce21765188708a8f689c62f43d1f

deliverables/ussuri/python-tackerclient.yaml

@@ -19,6 +19,10 @@ releases:
     projects:
       - repo: openstack/python-tackerclient
         hash: 7bda108ddfafc322687302d312e3e7b2fdeeb4c7
+  - version: ussuri-em
+    projects:
+      - repo: openstack/python-tackerclient
+        hash: 7bda108ddfafc322687302d312e3e7b2fdeeb4c7
 branches:
   - name: stable/ussuri
     location: 1.1.0

deliverables/ussuri/tacker-horizon.yaml

@@ -15,6 +15,10 @@ releases:
       - repo: openstack/tacker-horizon
         hash: ab081554d0c63a0459deae1fcb38ea663c1ca8ea
     diff-start: 0.15.0
+  - version: ussuri-em
+    projects:
+      - repo: openstack/tacker-horizon
+        hash: ab081554d0c63a0459deae1fcb38ea663c1ca8ea
 branches:
   - name: stable/ussuri
     location: 1.0.0.0rc1

deliverables/ussuri/tacker.yaml

@@ -23,6 +23,10 @@ releases:
     projects:
       - repo: openstack/tacker
         hash: 5783b9fff46544e1d50f1d3eafc254095f9f9b99
+  - version: ussuri-em
+    projects:
+      - repo: openstack/tacker
+        hash: 5783b9fff46544e1d50f1d3eafc254095f9f9b99
 branches:
   - name: stable/ussuri
     location: 3.0.0.0rc1