message: Install tornado if does not exist.
diff: #!/bin/bash
  +pip list | grep -F tornado
  +if [ $? -eq 1 ]
  + then
  + sudo pip install tornado
  +fi
  python sample_policy_manager.py --pack_port 8088 --unpack_port 8089 --add_http_header --encryption &
  POLICY_MANAGER=$!
  