Use full namespace so the example is runnable

Author: Nyholm

README.md

@@ -60,7 +60,7 @@ local Redis server and send some requests:
 
 ```php
 $loop = React\EventLoop\Factory::create();
-$factory = new Factory($loop);
+$factory = new \Clue\React\Redis\Factory($loop);
 
 $client = $factory->createLazyClient('localhost');
 $client->set('greeting', 'Hello world');