add initial github action

.github/workflows/ci.yml

@@ -0,0 +1,29 @@
+name: CI
+
+on:
+  push:
+    branches:
+      - '**'
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v2
+
+    - name: Read .nvmrc
+      id: nvmrc
+      run: echo "NODE_VERSION=$(cat .nvmrc)" >> $GITHUB_ENV
+
+    - name: Set up Node.js
+      uses: actions/setup-node@v2
+      with:
+        node-version: ${{ env.NODE_VERSION }}
+
+    - name: Install dependencies
+      run: npm install
+
+    - name: Run build
+      run: CI=false npm run build