Add ability to enable OSprofiler

To enable OSprofiler we should be able to add "profiler" notification
topic to ceilometer notification topics.

More about OSprofiler:
https://github.com/stackforge/osprofiler

More about ceilometer plugin:
https://review.openstack.org/#/c/100239/

Sample of trace (via Cinder and Nova Services):
http://pavlovic.me/rally/profiler/

Change-Id: I6137174a3ecddd58f62e0f98b235b71b1c070f13
diff --git a/lib/ceilometer b/lib/ceilometer
index eef6740..8ce9fb4 100644
--- a/lib/ceilometer
+++ b/lib/ceilometer
@@ -53,6 +53,9 @@
 CEILOMETER_SERVICE_HOST=$SERVICE_HOST
 CEILOMETER_SERVICE_PORT=${CEILOMETER_SERVICE_PORT:-8777}
 
+# To enable OSprofiler change value of this variable to "notifications,profiler"
+CEILOMETER_NOTIFICATION_TOPICS=${CEILOMETER_NOTIFICATION_TOPICS:-notifications}
+
 # Tell Tempest this project is present
 TEMPEST_SERVICES+=,ceilometer
 
@@ -141,7 +144,7 @@
 
     iniset_rpc_backend ceilometer $CEILOMETER_CONF DEFAULT
 
-    iniset $CEILOMETER_CONF DEFAULT notification_topics 'notifications'
+    iniset $CEILOMETER_CONF DEFAULT notification_topics "$CEILOMETER_NOTIFICATION_TOPICS"
     iniset $CEILOMETER_CONF DEFAULT verbose True
     iniset $CEILOMETER_CONF DEFAULT debug "$ENABLE_DEBUG_LOG_LEVEL"