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.
Just a thought that came to my mind just now; should we really add the ``verify_ssl`` and ``proxy_address`` values as parameters to the container – or should we alter the service definition (in the ``MannewHipchatExtension`` class) dynamically to make these calls?