Codecov integration

Author: lloc

README.md

@@ -7,6 +7,7 @@ Run `composer install --no-dev` if you plan to use the repository anyways.
 **Download the [latest stable from the WordPress Plugin Directory](http://downloads.wordpress.org/plugin/multisite-language-switcher.zip) and please, don't forget to give this plugin a (five) star-rating.**
 
 [![Scrutinizer Code Quality](https://scrutinizer-ci.com/g/lloc/Multisite-Language-Switcher/badges/quality-score.png?s=a2e5dbac2690bbd427f2d48b84473482e7e24fdb)](https://scrutinizer-ci.com/g/lloc/Multisite-Language-Switcher/)
+[![codecov](https://codecov.io/gh/lloc/Multisite-Language-Switcher/branch/master/graph/badge.svg?token=IlD4bX4KZ4)](https://codecov.io/gh/lloc/Multisite-Language-Switcher)
 
 A simple, powerful and easy to use plugin that will add 
 multilingual support to a WordPress