express-jwt-authz with Restify support

Per the suggestion by @adamjmcgrath https://github.com/auth0/express-jwt-authz/pull/45, express-jwt-authz has been forked to support restify.

Cheers!

From https://github.com/auth0/express-jwt-authz/pull/45...

Pretty basic change to support Restify's response object. Currently I'm using restify with express-jwt and express-jwt-authz but ran into a failure when scope is unexpected:

TypeError: res.append is not a function

Obviously this is because of the difference in Express and Restify's response object functions. Otherwise I haven't run into issues and it would be great to continue using these libraries.