Add coveralls badge to readme

Author: mikebronner

README.md

@@ -1,7 +1,7 @@
 [![Latest StableVersion](https://poser.pugx.org/toin0u/geocoder-laravel/v/stable.png)](https://packagist.org/packages/toin0u/geocoder-laravel)
 [![Total Downloads](https://poser.pugx.org/toin0u/geocoder-laravel/downloads.png)](https://packagist.org/packages/toin0u/geocoder-laravel)
 [![Build Status](https://ci.genealabs.com/build-status/image/1)](https://ci.genealabs.com/build-status/view/1)
-[Code Coverate Report](https://ci.genealabs.com/coverage/1)
+[![Coverage Status](https://coveralls.io/repos/geocoder-php/GeocoderLaravel/badge.png)](https://coveralls.io/r/geocoder-php/GeocoderLaravel)
 
 # Geocoder for Laravel