Guzzle Object to int
In  src/Ratchet/WebSocket/Version/RFC6455.php

line 52 .. 55

the function below throws a php notice ( Object of class Guzzle\Http\Message\Header could not be converted to int in /home/.../vendor/cboden/ratchet/src/Ratchet/WebSocket/Version/RFC6455.php on line 53) which in turn throws a 400 

```
/**
* {@inheritdoc}
*/
public function isProtocol(RequestInterface $request) {
    $version = (int)$request->getHeader('Sec-WebSocket-Version', -1);
    return ($this->getVersionNumber() === $version);
}
```

I got it to work like by calling it's toString magic method before converting to in
    /**
    \* {@inheritdoc}
    */
    public function isProtocol(RequestInterface $request) {
        $version = (int)$request->getHeader('Sec-WebSocket-Version', -1)->__toString();
        return ($this->getVersionNumber() === $version);
    }

Perhaps you can think of a better way? If it's just me you can ignore but I was going through the hello world example and I noticed it. 
