chore: Replace Travis build badge with GitHub Actions

README.md

@@ -2,7 +2,7 @@
 
 A headless [GraphQL](https://graphql.org/) ecommerce framework built on [Node.js](https://nodejs.org) with [Nest](https://nestjs.com/) with [TypeScript](http://www.typescriptlang.org/).
 
-[![Build Status](https://travis-ci.org/vendure-ecommerce/vendure.svg?branch=master)](https://travis-ci.org/vendure-ecommerce/vendure) [![lerna](https://img.shields.io/badge/maintained%20with-lerna-cc00ff.svg)](https://lernajs.io/)
+[![Build Status](https://github.com/vendure-ecommerce/vendure/workflows/Build%20&%20Test/badge.svg)](https://github.com/vendure-ecommerce/vendure/actions) [![lerna](https://img.shields.io/badge/maintained%20with-lerna-cc00ff.svg)](https://lernajs.io/)
 
 ### [www.vendure.io](https://www.vendure.io/)