Add service supervisor

This patch set adds supervisor mechanism for Watcher services
to get ability to track states.

Partially-Implements: blueprint watcher-service-list
Change-Id: Iab1cefb971c79ed27b22b6a5d1bed8698e35f9a4

watcher/tests/decision_engine/model/notification/fake_managers.py

@@ -26,6 +26,7 @@ class FakeManager(object):
 
     def __init__(self):
         self.api_version = self.API_VERSION
+        self.service_name = None
 
         # fake cluster instead on Nova CDM
         self.fake_cdmc = faker_cluster_state.FakerModelCollector()