Drop duplicate entry

README.md

 ## Components
 *Standalone components from web development frameworks and development groups.*
 
-* [Aura Components](http://auraphp.com/) - A package of PHP 5.4 components.
 * [CakePHP Plugins](http://plugins.cakephp.org/) - A directory of CakePHP plugins.
 * [Hoa Project](http://hoa-project.net/En/) - Another package of PHP components.
 * [League of Extraordinary Packages](https://thephpleague.com/) - A PHP package development group.