Add Github Actions CI

.github/workflows/ci.yml

@@ -0,0 +1,65 @@
+---
+name: Ruby CI
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  test:
+    name: test
+
+    runs-on: ubuntu-latest
+    if: |
+      !(   contains(github.event.pull_request.title,  '[ci skip]')
+        || contains(github.event.pull_request.title,  '[skip ci]'))
+
+    strategy:
+      matrix:
+        ruby-version: ['3.2', '3.1', '3.0', '2.7']
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Ruby ${{ matrix.ruby-version }}
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: ${{ matrix.ruby-version }}
+          bundler-cache: true
+
+      - name: Install dependencies
+        run: bundle install
+
+      - name: Run tests
+        run: |
+          ruby -v
+          bundle -v
+          bundle exec rake test
+
+  rubocop:
+    name: rubocop
+
+    runs-on: ubuntu-latest
+    if: |
+      !(   contains(github.event.pull_request.title,  '[ci skip]')
+        || contains(github.event.pull_request.title,  '[skip ci]'))
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: '2.7'
+          bundler-cache: true
+
+      - name: Install dependencies
+        run: bundle install
+
+      - name: Run Rubocop
+        run: |
+          ruby -v
+          bundle -v
+          bundle exec rubocop -v
+          bundle exec rubocop

.rubocop.yml

@@ -1,9 +1,11 @@
 AllCops:
   NewCops: enable
   SuggestExtensions: false
+  TargetRubyVersion: 2.7
   Exclude:
     - "doc/**/*"
     - "pkg/**/*"
+    - "vendor/**/*"
     - "minitest-rg.gemspec"
     - "Rakefile"
     - "Gemfile"