[Sprint 39] [master] XD-2333 Add Kafka integration test

  - Add kafka test support class that checks for kafka server availablity on localhost
     - This uses zk server available on default connect string `localhost:2181`
  - Add test for verifying kafka source and sink
     - having both the source/sink on the same test case will make sure the topic that
gets the data by kafka sink is actually read by kafka source
yeah, I had some timing issue with the kafka source not picking up the messages instantly and that's why added additional sleep time there. But, now I fixed the kafka source by setting the consumerTimeout to increased value.