Release watcher RC2 for Train

This release is being proposed to pick up translations and bugfixes
that have merged to stable/train but not been released.

Not all changes are critical to make it into the initial Train
coordinated release and can wait until a stable release later. If
this patch does not get an ack from the PTL and/or release liaison
by EOD Thursday it will just be abandoned.

Teams may also choose to -1 this patch and update it once any final
commits merge prior to the October 10 deadline.

Change-Id: Id04dcea4dceaaea31ae75bc394b04bf31a39cc3c

deliverables/train/watcher.yaml

@@ -25,6 +25,10 @@ releases:
     projects:
       - repo: openstack/watcher
         hash: d13adb4e3c16518f450b1646fdf5ffb73b95cfc5
+  - version: 3.0.0.0rc2
+    projects:
+      - repo: openstack/watcher
+        hash: 85763ccfce7937887cc7086b34c0255633c8b7e5
 branches:
   - name: stable/train
     location: 3.0.0.0rc1