Updated readme on middleware setup section

included fully qualified name for request middleware in app/Http/Kernel.php to get it working in laravel 5.5

Author: Tumaini Mosha

README.md

@@ -23,7 +23,7 @@ In `app/Http/Kernel.php`
 ```php
  protected $routeMiddleware = [
  /// Other Middleware
- 'xml' => XmlRequestMiddleware::class,
+ 'xml' => \XmlMiddleware\XmlRequestMiddleware::class,
  ];
 ```