Update README.md

Author: bhubbard

README.md

@@ -3,6 +3,7 @@
 [![Code Climate](https://codeclimate.com/github/wp-bootstrap/wp-bootstrap-navwalker/badges/gpa.svg)](https://codeclimate.com/github/wp-bootstrap/wp-bootstrap-navwalker)
 [![Test Coverage](https://codeclimate.com/github/wp-bootstrap/wp-bootstrap-navwalker/badges/coverage.svg)](https://codeclimate.com/github/wp-bootstrap/wp-bootstrap-navwalker/coverage)
 [![Issue Count](https://codeclimate.com/github/wp-bootstrap/wp-bootstrap-navwalker/badges/issue_count.svg)](https://codeclimate.com/github/wp-bootstrap/wp-bootstrap-navwalker)
+[![Build Status](https://travis-ci.org/wp-bootstrap/wp-bootstrap-navwalker.svg?branch=master)](https://travis-ci.org/wp-bootstrap/wp-bootstrap-navwalker)
 
 A custom WordPress nav walker class to fully implement the Bootstrap 3.0+ navigation style in a custom theme using the WordPress built in menu manager.