Update 2.2 badge.

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>

README.md

@@ -1,9 +1,9 @@
 PHP library for building API Client SDK for PHP
 ==============
 
-[![Build Status](https://travis-ci.org/laravie/codex.svg?branch=1.6)](https://travis-ci.org/laravie/codex)
+[![Build Status](https://travis-ci.org/laravie/codex.svg?branch=2.2)](https://travis-ci.org/laravie/codex)
 [![Latest Stable Version](https://poser.pugx.org/laravie/codex/v/stable)](https://packagist.org/packages/laravie/codex)
 [![Total Downloads](https://poser.pugx.org/laravie/codex/downloads)](https://packagist.org/packages/laravie/codex)
 [![Latest Unstable Version](https://poser.pugx.org/laravie/codex/v/unstable)](https://packagist.org/packages/laravie/codex)
 [![License](https://poser.pugx.org/laravie/codex/license)](https://packagist.org/packages/laravie/codex)
-[![Coverage Status](https://coveralls.io/repos/github/laravie/codex/badge.svg?branch=1.6)](https://coveralls.io/github/laravie/codex?branch=1.6)
+[![Coverage Status](https://coveralls.io/repos/github/laravie/codex/badge.svg?branch=2.2)](https://coveralls.io/github/laravie/codex?branch=2.2)