wip: add tracing

* tracing info should ideally be passed in message object
* and not payload - this is temp while we update bus-api
* to allow "trace" field in message

Author: rakibansary

src/app.js

@@ -65,7 +65,7 @@ const dataHandler = (messageSet, topic, partition) => Promise.each(messageSet, a
     } = {
       traceId: null,
       parentSegmentId: null
-    } } = messageJSON;
+    } } = messageJSON.payload;
 
     console.log('tracing information', traceId, parentSegmentId);