doc: adding thlorenz to list of collaborators

Reviewed-By: Chris Dickinson <christopher.s.dickinson@gmail.com>, Jeremiah Senkpiel <fishrock123@rocketmail.com>, Bert Belder <bertbelder@gmail.com>
PR-URL: nodejs#577

Author: thlorenz

README.md

@@ -209,6 +209,7 @@ information about the governance of the io.js project, see
 * **Colin Ihrig** ([@cjihrig](https://github.com/cjihrig)) <cjihrig@gmail.com> (Technical Committee)
 * **Mikeal Rogers** ([@mikeal](https://github.com/mikeal)) <mikeal.rogers@gmail.com>
 * **Rod Vagg** ([@rvagg](https://github.com/rvagg)) <rod@vagg.org>
+* **Thorsten Lorenz** ([@thlorenz](https://github.com/thlorenz)) <thlorenz@gmx.de>
 
 Collaborators follow the [COLLABORATOR_GUIDE.md](./COLLABORATOR_GUIDE.md) in
 maintaining the io.js project.