added test tag

Author: allenhwkim

README.md

@@ -1,5 +1,6 @@
 # ng2-datetime-picker
 
+[![Build Status](https://travis-ci.org/ng2-ui/ng2-datetime-picker.svg?branch=master)](https://travis-ci.org/ng2-ui/ng2-datetime-picker)
 [![Join the chat at https://gitter.im/ng2-ui/ng2-datetime-picker](https://badges.gitter.im/ng2-ui/ng2-datetime-picker.svg)](https://gitter.im/ng2-ui/ng2-datetime-picker?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 AngularJS 2 DateTime Picker