Add Ceilometer client for scenarios tests

Ceilometer client is needed for scenario test
of ceilometer features.

blueprint add-ceilometer-scenario-tests

Change-Id: Ic1b8b7ea41cdabd74e9be951625b74298312880b
diff --git a/tempest/scenario/manager.py b/tempest/scenario/manager.py
index db26bda..c836227 100644
--- a/tempest/scenario/manager.py
+++ b/tempest/scenario/manager.py
@@ -82,6 +82,7 @@
         cls.object_storage_client = cls.manager.object_storage_client
         cls.orchestration_client = cls.manager.orchestration_client
         cls.data_processing_client = cls.manager.data_processing_client
+        cls.ceilometer_client = cls.manager.ceilometer_client
         cls.resource_keys = {}
         cls.os_resources = []