Migrate to aodh for OS::Ceilometer::Alarm

This changes:
1. use aodhclient to manage OS::Ceilometer::Alarm
resource, including create, update, delete, check, suspend,
resume and show.
2. rename OS::Ceilometer::Alarm to OS::Aodh::Alarm
3. considering to compatible with old templates with resource
OS::Ceilometer::Alarm, set resource_registry to map Ceilometer alarm
to Aodh alarm

Blueprint migrate-to-use-aodh-for-alarms

Change-Id: I6e2d14f15a345b927b53adc237cf2bf4010842f0
diff --git a/scenario/templates/test_ceilometer_alarm.yaml b/scenario/templates/test_aodh_alarm.yaml
similarity index 96%
rename from scenario/templates/test_ceilometer_alarm.yaml
rename to scenario/templates/test_aodh_alarm.yaml
index 01bc790..9218f56 100644
--- a/scenario/templates/test_ceilometer_alarm.yaml
+++ b/scenario/templates/test_aodh_alarm.yaml
@@ -15,7 +15,7 @@
       cooldown: 0
       scaling_adjustment: 1
   alarm:
-    type: OS::Ceilometer::Alarm
+    type: OS::Aodh::Alarm
     properties:
       description: Scale-up if the average CPU > 50% for 1 minute
       meter_name: test_meter