test: Run test in github actions

Replaces the old circleci tests.

Test node 12-16

Previously we were only testing node 12. This adds some newer versions.
In local testing, node 18 and 20 don't work.

.github/workflows/nodejs.yml

@@ -0,0 +1,27 @@
+name: Node.js CI
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+#
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        node-version: [12.x, 14.x, 16.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 --if-present
+      - run: npm test
+