Create basic github actions workflow

From: https://docs.github.com/en/actions/automating-builds-and-tests/building-and-testing-nodejs

.github/workflows/tests.yml

@@ -0,0 +1,25 @@
+name: Unit tests
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        node-version: [14.x, 16.x, 18.x]
+
+    steps:
+      - uses: actions/checkout@v3
+      - name: Use Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v3
+        with:
+          node-version: ${{ matrix.node-version }}
+      - run: npm ci
+      - run: npm run build
+      - run: npm run test