[specs] Moved worker class to support.

* This is to improve other tests.
[specs] Refactoring: Moved notifications specs to separate file.
Added (basic) Hipchat support: Post in one central room, when bucket failed.

* Added "hipchat" gem dependency
* Refactored Build#short_identifier
* Added basic hipchat config
* Send a hipchat message, when bucket failed.
* [spec] Removed fixtures from notification_spec and replaced it with a mix of real and double objects.
* [spec] Stub all HipChat calls.
Hipchat message now has correct color (red if failed).
[spec] Refactored notification_spec.rb
[spec] Refactored hipchat tests in notification_spec.rb
Extracted hipchat_room to own method to clean up specs.
Sent hipchat message, when bucket was repaired.
[spec] Refactored "sends no email" specs.
[spec] Ensure, that hipchat is not called, when bucket succeeded.
Merge pull request #23 from apepper/hipchat

Basic HipChat support