Update README.md

Author: Igor Chepurnoy

README.md

@@ -8,6 +8,7 @@ Yii2-rbac provides a web interface for advanced access control and includes foll
 - Integrated with [yii2mod/base](https://github.com/yii2mod/base)
 
 [![Latest Stable Version](https://poser.pugx.org/yii2mod/yii2-rbac/v/stable)](https://packagist.org/packages/yii2mod/yii2-rbac) [![Total Downloads](https://poser.pugx.org/yii2mod/yii2-rbac/downloads)](https://packagist.org/packages/yii2mod/yii2-rbac) [![License](https://poser.pugx.org/yii2mod/yii2-rbac/license)](https://packagist.org/packages/yii2mod/yii2-rbac)
+[![Build Status](https://travis-ci.org/yii2mod/yii2-rbac.svg?branch=master)](https://travis-ci.org/yii2mod/yii2-rbac)
 
 Installation
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