Add badges

Author: Márk Sági-Kazár

README.md

@@ -2,6 +2,9 @@
 
 [![Latest Version](https://img.shields.io/github/release/php-http/promise.svg?style=flat-square)](https://github.com/php-http/promise/releases)
 [![Software License](https://img.shields.io/badge/license-MIT-brightgreen.svg?style=flat-square)](LICENSE)
+[![Build Status](https://img.shields.io/travis/php-http/promise.svg?style=flat-square)](https://travis-ci.org/php-http/promise)
+[![Code Coverage](https://img.shields.io/scrutinizer/coverage/g/php-http/promise.svg?style=flat-square)](https://scrutinizer-ci.com/g/php-http/promise)
+[![Quality Score](https://img.shields.io/scrutinizer/g/php-http/promise.svg?style=flat-square)](https://scrutinizer-ci.com/g/php-http/promise)
 [![Total Downloads](https://img.shields.io/packagist/dt/php-http/promise.svg?style=flat-square)](https://packagist.org/packages/php-http/promise)
 
 **Promise used for asynchronous HTTP requests.**
@@ -20,7 +23,7 @@ $ composer require php-http/promise
 
 ## Documentation
 
-Please see the [official documentation](http://docs.httplug.io).
+Please see the [official documentation](http://docs.php-http.org).
 
 
 ## Testing