Enable CI with GitHub Actions

Author: ggrossetie

.github/workflows/ci.yml

@@ -0,0 +1,25 @@
+name: CI
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - '*'
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+
+    # We are still using Node 10 for performance reasons
+    # Asciidoctor.js performance are not great on Node > 10  
+    - name: Use Node.js 10
+      uses: actions/setup-node@v1
+      with:
+        node-version: '10'
+    - run: npm ci
+    - run: npm t