Create pull_request.yml

.github/workflows/pull_request.yml

@@ -0,0 +1,24 @@
+name: Build PR
+on: [pull_request]
+
+jobs:
+  build:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        node-version: [12.x]
+        os: [ubuntu-latest]
+    steps:
+    - uses: actions/checkout@v1
+    - name: Use Node.js ${{ matrix.node_version }}
+      uses: actions/setup-node@v1
+      with:
+        node-version: ${{ matrix.node_version }}
+    - name: npm install, build, and test
+      run: |
+        npm install
+        npm run start -- --testMode
+        npm run demo
+        npm run coverage
+      env:
+        CI: true