Merge pull request #38 from lyrixx/patch-1

Added twitter SDK

README.md

 * [OAuth2](https://github.com/php-loep/oauth2-server) - An OAuth2 authentication server, resource server and client library.
 * [PHP oAuthLib](https://github.com/Lusitanian/PHPoAuthLib) - Another OAuth library. 
 * [TwitterOAuth](https://github.com/ruudk/twitteroauth) - A Twitter OAuth library.
+* [TwitterSDK](https://github.com/lyrixx/twitter-sdk) - A Twitter SDK, fully tested.
 * [Hawk](https://github.com/dflydev/dflydev-hawk) - A Hawk HTTP authentication library.
 
 ## Markup
 * Collecting Garbage: [1](http://www.php.net/manual/en/features.gc.refcounting-basics.php) [2](http://www.php.net/manual/en/features.gc.collecting-cycles.php) [3](http://www.php.net/manual/en/features.gc.performance-considerations.php) - A series about the PHP garbage collection internals.
 
 # Contributing
-Please see [CONTRIBUTING](https://github.com/ziadoz/awesome-php/blob/master/CONTRIBUTING.md) for details.
+Please see [CONTRIBUTING](https://github.com/ziadoz/awesome-php/blob/master/CONTRIBUTING.md) for details.