Added badge license

Author: moritzmock

readme.md

@@ -2,6 +2,7 @@ Internationalization
 ====================
 
 [![npm version](https://badge.fury.io/js/%40aboutbits%2Finternationalization.svg)](https://badge.fury.io/js/%40aboutbits%2Finternationalization)
+[![GitHub license](https://img.shields.io/github/license/aboutbits/internationalization)](https://github.com/aboutbits/internationalization/blob/master/license.md)
 
 This package includes utilities for working with different languages in the browser. 
 This package works for client side rendered applications as well as for server side rendered applications.