switch from Travis to GitHub Actions

.github/workflows/node.yml

@@ -0,0 +1,22 @@
+name: Node
+on: [push, pull_request]
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v2
+
+    - name: Setup Node
+      uses: actions/setup-node@v1
+      with:
+        node-version: 20
+
+    - name: Install dependencies
+      run: npm ci
+
+    - name: Build the bundle
+      run: npm run build
+
+    - name: Run tests
+      run: npm test

README.md

@@ -1,4 +1,4 @@
-# Delaunator [![Build Status](https://app.travis-ci.com/mapbox/delaunator.svg?branch=main)](https://app.travis-ci.com/mapbox/delaunator) [![](https://img.shields.io/badge/simply-awesome-brightgreen.svg)](https://github.com/mourner/projects) [![](https://badgen.net/bundlephobia/minzip/delaunator)](https://unpkg.com/delaunator)
+# Delaunator [![](https://img.shields.io/badge/simply-awesome-brightgreen.svg)](https://github.com/mourner/projects) [![](https://badgen.net/bundlephobia/minzip/delaunator)](https://unpkg.com/delaunator)
 
 An incredibly fast and robust JavaScript library for
 [Delaunay triangulation](https://en.wikipedia.org/wiki/Delaunay_triangulation) of 2D points.