Extend Hipchat Service (BB-3456)

Please extend the Hipchat service to allow for assigning value to two additional parameters:

• notify : 0 = false, 1 = true. (default: 0)
• color : "yellow", "red", "green", "purple", or "random". (default: yellow)

[[https://www.hipchat.com/docs/api/method/rooms/message|The Hipchat API]]

My original request for this broker was based on [[https://bitbucket.org/nskerl/hipchatbroker|this project]]
and this [[https://bitbucket.org/site/master/issue/2800/new-broker-hip-chat-bb-1985|BB issue]].

If you would like I can make the change there, however Im not sure you based the Bitbucket Service on this repo or not. It might be easiest for you guys to change directly in your implementation.

Thanks,

Nathan