Add verify_ssl and proxy_address bundle options.

This will allow setting these options on the HipChat service.
The HipChat package requirement in Composer is updated to dev.
This is needed because the verify_ssl en proxy options are not present
in the latest stable tag.
Update Composer hipchat-php dependency to use stable tag.
Refactor tests.
Merge pull request #4 from shirshir/add-extra-config-options

Add verify_ssl and proxy_address bundle options.
Merge branch 'develop' of github.com:ManneW/HipChatBundle

* 'develop' of github.com:ManneW/HipChatBundle:
  Hopefully fixed the Travis CI configuration.
  Updated Travis CI configuration to also test against PHP 5.6 and HHVM.