Added gerritbot to openstack-ansible channel

This change adds the gerrit irc bot to the openstack-ansible channel.
The bot has been setup to watch the branches **stable/icehouse**,
**stable/juno**, and **proposed/juno**.

Change-Id: I00a373744faeef9a8243c9df5edd8c83775f3cd8

gerritbot/channels.yaml

@@ -1031,3 +1031,17 @@ striker-dev:
       - stackforge/striker
     branches:
       - master
+
+openstack-ansible:
+    events:
+      - patchset-created
+      - change-merged
+      - x-vrif-minus-2
+    projects:
+      - stackforge/os-ansible-deployment
+    branches:
+      - master
+      - stable/icehouse
+      - stable/juno
+      - proposed/juno
+