Add support for support WAMP CRA

[jonahzheng]

bonefish support Authentication?
ex. WAMP CRA
https://github.com/crossbario/crossbar-examples/blob/master/authentication/wampcra/static/web/index.html

[davidchappelle]

I will look into adding support for this. May need to first add support for this to autobahn-cpp if it doesn't already exist.