Use defined headers

[DeveloperMarius]

Hey,

I'm using socketio-jwt (NodeJS Server Side Package) to check for a Authorization header and validate it using jwt.
For that I need to add a header, but elephant.io never applys defined headers. I don't know why and I hope it is the right place to add them.

$elephant = new ElephantIO\Client(new \ElephantIO\Engine\SocketIO\Version3X('https://domain.de:4101', array(
                'headers' => [
                    'Authorization: Bearer tokenabc'
                ]
            )));

Looking forward to your feedback^^

~ Marius