Add Cinder Stein Cycle Highlights

This patch adds the requested Cycle Highlights for Cinder during
the Stein development cycle.

Change-Id: Ib9a30be69a0cc90a3da21e08a4fcb914a9b485df

deliverables/stein/cinder.yaml

@@ -3,5 +3,11 @@ launchpad: cinder
 release-model: cycle-with-rc
 team: cinder
 type: service
+cycle-highlights:
+  - 'Added multiattach and deferred deletion support for the RBD driver.'
+  - 'Numerous bug fixes have been integrated to address stability and reliability.'
+  - 'User experience improvements around driver initialization, data retained
+     during volume transfers and the information returned by commands.'
+  - 'Continued improvements in the backup service.'
 repository-settings:
   openstack/cinder: {}