Update CI badge

Author: gpotter2

README.md

@@ -2,7 +2,7 @@
 
 [![NPM](https://nodei.co/npm/lambda-local.png?compact=true)](https://nodei.co/npm/lambda-local/)
 
-[![Build Status](https://travis-ci.org/ashiina/lambda-local.svg?branch=develop)](https://travis-ci.org/ashiina/lambda-local)
+[![Lambda-local unit tests](https://github.com/ashiina/lambda-local/actions/workflows/unittests.yml/badge.svg?branch=develop&event=push)](https://github.com/ashiina/lambda-local/actions?query=event%3Apush)
 
 Lambda-local lets you test **NodeJS Amazon Lambda functions** on your local machine, by providing a simplistic API and command-line tool.