Function scrappy_web_actors::ws::start

pub fn start<A, T>(
    actor: A, 
    req: &HttpRequest, 
    stream: T
) -> Result<HttpResponse, Error> where
    A: Actor<Context = WebsocketContext<A>> + StreamHandler<Result<Message, ProtocolError>>,
    T: Stream<Item = Result<Bytes, PayloadError>> + 'static, 

Do websocket handshake and start ws actor.