CI: Use GitHub Actions

Author: remram44

.github/workflows/test.yml

@@ -0,0 +1,21 @@
+name: Test
+
+on:
+  - push
+  - pull_request
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - uses: actions/setup-python@v1
+      with:
+        python-version: "3.7"
+    - name: Install dependencies
+      run: |
+        sudo apt-get update -qq
+        sudo apt-get install -yy default-jre-headless
+        pip install html5validator
+    - name: Validate HTML
+      run: html5validator --show-warnings