Code Changes includes:
 1.Sychronizer for ceilometer service.
 2.Added files:
   i.xos/synchronizer/steps/sync_ceilometerservice.py(Ceilometer sychronizer )
   ii.xos/synchronizer/steps/sync_ceilometerservice.yaml(Ansible yaml file which will be run as part of sychronizer)
   iii.xos/synchronizer/templates/update-keystone-endpoints.py.j2 (to change endpoints in keystone)
 3.Modified init script of ceilometer service image for starting pub-sub module
 4. [api] default_api_return_limit = 1000 in README and ceilometer.conf.j2 for both mitaka-v2 and mitaka-v3

Change-Id: I2ab935c2fc507a00729d14cf87bae81990b75ed9
diff --git a/xos/models.py b/xos/models.py
index 4ab3c15..0960152 100644
--- a/xos/models.py
+++ b/xos/models.py
@@ -19,6 +19,8 @@
     LOOK_FOR_IMAGES=[ "ceilometer-service-trusty-server-multi-nic",
                     ]
 
+    sync_attributes = ("private_ip", "private_mac",
+                       "nat_ip", "nat_mac", )
     class Meta:
         app_label = "monitoring"
         verbose_name = "Ceilometer Service"