ci: add PR test script

Author: kevinchappell

.github/workflows/pull-request.yml

@@ -0,0 +1,19 @@
+on: pull_request
+name: Pull Request
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        node: [12]
+    steps:
+      - uses: actions/checkout@v2
+      - name: Set up Nodejs ${{ matrix.node }}
+        uses: actions/setup-node@v1
+      - name: Install dependencies
+        env:
+          CI: true
+        run: npm install
+      - name: Test
+        run: npm test