[trove] 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: I1ce7b6f6366fd584a12008e8dccb531b827af9e7

deliverables/train/python-troveclient.yaml

@@ -23,6 +23,10 @@ releases:
     projects:
       - repo: openstack/python-troveclient
         hash: 564edb7f63ffdc8ae9e0e9fb33afbf4bf60902ce
+  - version: train-em
+    projects:
+      - repo: openstack/python-troveclient
+        hash: 564edb7f63ffdc8ae9e0e9fb33afbf4bf60902ce
 branches:
   - name: stable/train
     location: 3.0.0

deliverables/train/trove-dashboard.yaml

@@ -15,6 +15,10 @@ releases:
       - repo: openstack/trove-dashboard
         hash: 1879195d64b877e167534ba4371dfda6d4ed1672
     diff-start: 12.0.0
+  - version: train-em
+    projects:
+      - repo: openstack/trove-dashboard
+        hash: 1879195d64b877e167534ba4371dfda6d4ed1672
 branches:
   - name: stable/train
     location: 13.0.0.0rc1

deliverables/train/trove.yaml

@@ -33,6 +33,10 @@ releases:
     projects:
       - repo: openstack/trove
         hash: d8b5525fd2a544c264a86edcd0d3493709f262af
+  - version: train-em
+    projects:
+      - repo: openstack/trove
+        hash: d8b5525fd2a544c264a86edcd0d3493709f262af
 branches:
   - name: stable/train
     location: 12.0.0.0rc1