Test a PR

.github/workflows/test-pr.yml

@@ -0,0 +1,14 @@
+name: Test Pull Request
+
+on:
+  pull_request:
+    branches:
+    - master
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v1
+    - name: Build the Docker image
+      run: docker build . --file Dockerfile