Expose websocket TLSClientConfig

[techjanitor]

I think it would be good to have the option to configure TLSClientConfig in Gorilla websocket. This would enable the utilization of unsigned certs which seems to be an impossibility right now for wss (?)

http://godoc.org/github.com/gorilla/websocket#Dialer

&tls.Config{InsecureSkipVerify: true}
&tls.Config{RootCAs: certs}

It could potentially be a setting in the Client struct, much like how Kite has TLSConfig for its listener. Or it could just inherit c.LocalKite.TLSConfig when c.dial initializes &sockjsclient.DialOptions.

In addition, a method of setting the TLSConfig for k.kontrol.Client would be useful as well.

I tried to implement this myself but I ran into some strange issues with heartbeat session authentication between a client and kontrol.