Replace Travis CI with GitHub Actions

.github/workflows/ci.yml

@@ -0,0 +1,32 @@
+name: CI
+
+on:
+  push:
+    branches: ['*']
+  pull_request:
+    branches: [main]
+
+jobs:
+  test:
+    name: Run tests (Node.js ${{ matrix.node }})
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        node: [18, 20, 22]
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Use Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: ${{ matrix.node }}
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Run tests
+        run: npm run test