Repository creation now just takes in an http.RoundTripper. Authenticated requests or requests which require additional headers should use the NewTransport function along with a request modifier (such an an authentication handler).
Signed-off-by: Derek McGowan <derek@mcgstyle.net> (github: dmcgowan)
Refactory authorizer to take a set of authentication handlers for different authentication schemes returned by an unauthorized HTTP requst.
Signed-off-by: Derek McGowan <derek@mcgstyle.net> (github: dmcgowan)
