Update build status badge to GitHub Actions

Author: andi

README.md

@@ -1,7 +1,7 @@
 # Simple Navigation
 
 [![Gem Version](https://badge.fury.io/rb/simple-navigation.png)](http://badge.fury.io/rb/simple-navigation)
-[![Build Status](https://secure.travis-ci.org/codeplant/simple-navigation.png?branch=master)](http://travis-ci.org/codeplant/simple-navigation)
+[![Build Status](https://github.com/codeplant/simple-navigation/actions/workflows/ci.yml/badge.svg?branch=master)](https://github.com/codeplant/simple-navigation/actions/workflows/ci.yml)
 [![Code Climate](https://codeclimate.com/github/codeplant/simple-navigation.png)](https://codeclimate.com/github/codeplant/simple-navigation)
 [![Coverage Status](https://coveralls.io/repos/codeplant/simple-navigation/badge.png)](https://coveralls.io/r/codeplant/simple-navigation)