Fixed tracker_response for Streaming API example

Author: roshanijawale

example/Streaming_API/streaming.py

@@ -6,7 +6,7 @@
     'message': lambda message: print('printing the message response ', str(message))
    # ,'message_response': lambda message: print('printing the transcription', str(message))
    # ,'insight_response': lambda insight: print('printing the insight response ', str(insight))
-    #,'tracker_response': lambda tracker: print('printing the tracker response ', str(tracker))
+    ,'tracker_response': lambda tracker: print('printing the tracker response ', str(tracker))
    # ,'topic_response': lambda topic: print('printing the topic response ', str(topic))
 }