update readme badge (#171)

Co-authored-by: Bart Veneman <bartveneman@users.noreply.github.com>

Author: bartveneman

readme.md

@@ -1,7 +1,7 @@
 # css-analyzer
 
 [![NPM Version](https://img.shields.io/npm/v/@projectwallace/css-analyzer.svg)](https://www.npmjs.com/package/@projectwallace/css-analyzer)
-[![Build Status](https://travis-ci.org/projectwallace/css-analyzer.svg?branch=master)](https://travis-ci.org/projectwallace/css-analyzer)
+![Node.js CI](https://github.com/projectwallace/css-analyzer/workflows/Node.js%20CI/badge.svg)
 [![Known Vulnerabilities](https://snyk.io/test/github/projectwallace/css-analyzer/badge.svg)](https://snyk.io/test/github/projectwallace/css-analyzer)
 [![Coverage Status](https://coveralls.io/repos/github/projectwallace/css-analyzer/badge.svg?branch=master)](https://coveralls.io/github/projectwallace/css-analyzer?branch=master)
 ![Dependencies Status](https://img.shields.io/david/projectwallace/css-analyzer.svg)