[Core] Add spec for 'topic' service

Add spec for a 'topic' service which will provide
the ability for messaging within a local instance
of an application. WTD-1329.

platform/core/test/suite.json

@@ -25,6 +25,7 @@
 
     "services/Now",
     "services/Throttle",
+    "services/Topic",
 
     "types/MergeModels",
     "types/TypeCapability",
@@ -35,4 +36,4 @@
 
     "views/ViewCapability",
     "views/ViewProvider"
-]
+]