Add CI using GitHub Actions

.github/workflows/ci.yml

@@ -0,0 +1,35 @@
+---
+name: CI
+
+on:
+  pull_request:
+  push:
+    branch: master
+
+concurrency:
+  group: ${{ github.ref_name }}
+  cancel-in-progress: true
+
+jobs:
+  unit:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - ruby: '2.7'
+            puppet: 7
+          - ruby: '3.2'
+            puppet: 8
+    env:
+      PUPPET_GEM_VERSION: "~> ${{ matrix.puppet }}.0"
+    name: "Ruby ${{ matrix.ruby }} with Puppet ${{ matrix.puppet }}"
+    steps:
+      - uses: actions/checkout@v4
+      - name: Setup ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: ${{ matrix.ruby }}
+          bundler-cache: true
+      - name: Run tests
+        run: bundle exec rake test

Gemfile

@@ -2,6 +2,4 @@ source 'https://rubygems.org'
 
 gemspec
 
-puppet_version = ENV['PUPPET_VERSION']
-puppet_spec = puppet_version ? "~> #{puppet_version}" : '< 7.0.0'
-gem 'puppet', puppet_spec
+gem 'puppet', ENV.fetch('PUPPET_GEM_VERSION', '< 9')