[ci] setup github actions

.github/workflows/nodejs.yml

@@ -0,0 +1,20 @@
+name: Node CI
+
+on: [push]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v1
+    - name: Use Node.js
+      uses: actions/setup-node@v1
+      with:
+        node-version: '12.x'
+    - name: test
+      run: |
+        yarn
+        yarn test
+      env:
+        CI: true
+        TEST: true