Change use path for Symfony Event

Author: DariusIII

lib/Tmdb/Event/RequestEvent.php

@@ -12,7 +12,7 @@
  */
 namespace Tmdb\Event;
 
-use Symfony\Component\EventDispatcher\Event;
+use Symfony\Contracts\EventDispatcher\Event;
 use Tmdb\Common\ParameterBag;
 use Tmdb\HttpClient\Request;
 use Tmdb\HttpClient\Response;