Update README.md

Author: Igor Chepurnoy

README.md

@@ -3,6 +3,7 @@ Enumerable helper
 An enumeration implementation for Yii Framework 2.0
 
 [![Latest Stable Version](https://poser.pugx.org/yii2mod/yii2-enum/v/stable)](https://packagist.org/packages/yii2mod/yii2-enum) [![Total Downloads](https://poser.pugx.org/yii2mod/yii2-enum/downloads)](https://packagist.org/packages/yii2mod/yii2-enum) [![License](https://poser.pugx.org/yii2mod/yii2-enum/license)](https://packagist.org/packages/yii2mod/yii2-enum)
+[![Build Status](https://travis-ci.org/yii2mod/yii2-enum.svg?branch=master)](https://travis-ci.org/yii2mod/yii2-enum)
 
 Installation
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