Fix GitHub Actions run by updating Node.js version

.github/workflows/main.yml

@@ -0,0 +1,19 @@
+name: CI
+
+on: [push]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Use Node.js 16.x
+      uses: actions/setup-node@v2
+      with:
+        node-version: '16.x'
+    - name: npm install, build, and test
+      run: |
+        npm ci
+        npm run build