added hipchat notification tool

Tool sends message to hipchat showing the state of the execution of a
given command:

* give hipchat configuration (apikey, room and sender)
* give message
* give command to execute

The given message is shown in:
* green if the command execution returned 0
* red if teh command failed
forward stdout and stderr in hipchat notifyer
Initial commit
also forward environment to command
add README.md