Update README.md

Author: risenW

README.md

@@ -8,6 +8,7 @@
 ## danfojs: powerful javascript data analysis toolkit 
 ![Node.js CI](https://github.com/opensource9ja/danfojs/workflows/Node.js%20CI/badge.svg?branch=master)
 [![](https://data.jsdelivr.com/v1/package/npm/danfojs/badge?style=rounded)](https://www.jsdelivr.com/package/npm/danfojs)
+[![Build Status](https://travis-ci.org/opensource9ja/danfojs.svg?branch=master)](https://travis-ci.org/opensource9ja/danfojs)
 ![Twitter](https://img.shields.io/twitter/url?style=social&url=https%3A%2F%2Ftwitter.com%2FDanfoJs)