add ci icon

Author: wujunze

README.md

@@ -2,6 +2,10 @@
 Simple and easy to use the PHP command-line output of color
 
 
+
+<p align="center">
+<a href="https://travis-ci.org/wujunze/php-cli-color"><img src="https://travis-ci.org/wujunze/php-cli-color.svg?branch=master" alt="Build Status"></a>
+</p>
 ## Installation
 
 `composer require wujunze/php-cli-color '~1.0'`