[tacker] Transition Rocky to EM

This transition the rocky 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: I21fc820c305389ff88e180c4aa36459c0fe652fe

deliverables/rocky/python-tackerclient.yaml

@@ -19,6 +19,10 @@ releases:
     projects:
       - repo: openstack/python-tackerclient
         hash: 71897e549f4f97db3df66522562fb8c702c379f6
+  - version: rocky-em
+    projects:
+      - repo: openstack/python-tackerclient
+        hash: 71897e549f4f97db3df66522562fb8c702c379f6
 branches:
   - name: stable/rocky
     location: 0.14.0

deliverables/rocky/tacker-horizon.yaml

@@ -11,5 +11,9 @@ releases:
       - hash: b701cb4d494cd05a409915aa7a455670f1b30dc6
         repo: openstack/tacker-horizon
     version: 0.12.0
+  - version: rocky-em
+    projects:
+      - repo: openstack/tacker-horizon
+        hash: b701cb4d494cd05a409915aa7a455670f1b30dc6
 repository-settings:
   openstack/tacker-horizon: {}

deliverables/rocky/tacker.yaml

@@ -11,6 +11,10 @@ releases:
     projects:
       - repo: openstack/tacker
         hash: 5987ad8c56a61e3a6d8fcf37a2557926c585de41
+  - version: rocky-em
+    projects:
+      - repo: openstack/tacker
+        hash: 5987ad8c56a61e3a6d8fcf37a2557926c585de41
 cycle-highlights:
   - VNF Forwarding Graph support for Network Service. Operators can
     describe VNFFGD inside NSD to define the network connections among