Add GitHub Action for validating website (#64)

.github/workflows/jekyll.yml

@@ -0,0 +1,20 @@
+name: Jekyll site CI
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Build the site in the jekyll/builder container
+      run: |
+        docker run \
+        -v ${{ github.workspace }}:/srv/jekyll -v ${{ github.workspace }}/_site:/srv/jekyll/_site \
+        jekyll/builder:latest /bin/bash -c "chmod 777 /srv/jekyll && jekyll build --future && find /srv/jekyll/_site -type f -name '*.html' -exec xmllint --noout {} \; && wget https://github.com/validator/validator/releases/download/18.11.5/vnu.jar_18.11.5.zip && unzip -p vnu.jar_18.11.5.zip dist/vnu.jar > vnu.jar && java -jar vnu.jar --skip-non-html /srv/jekyll/_site"

.gitignore

@@ -1,3 +1,4 @@
 _site
 .sass-cache
 vnu.jar
+.DS_Store

.travis.yml

@@ -1,19 +0,0 @@
-language: ruby
-rvm:
-  - 2.5.3
-sudo: false
-install: gem install github-pages
-script:
-  - jekyll build
-  - jekyll doctor
-  - find _site -type f -name '*.html' -exec xmllint --noout {} \;
-  - curl -L -O https://github.com/validator/validator/releases/download/18.11.5/vnu.jar_18.11.5.zip
-  - unzip -p vnu.jar_18.11.5.zip dist/vnu.jar > vnu.jar
-  - java -jar vnu.jar --skip-non-html _site
-addons:
-  apt:
-    packages:
-      - curl
-      - default-jre
-      - libxml2-utils
-      - unzip

README.markdown

@@ -1,4 +1,4 @@
-# Sparkle Website [![Build Status](https://travis-ci.org/sparkle-project/sparkle-project.github.io.svg?branch=master)](https://travis-ci.org/sparkle-project/sparkle-project.github.io)
+# Sparkle Website ![Build Status](https://github.com/sparkle-project/sparkle-project.github.io/workflows/Jekyll%20site%20CI/badge.svg?branch=master)
 
 Website for Sparkle, an easy-to-use software update framework for macOS applications.