Add GitHub Actions for RSpec

.github/workflows/main.yaml

@@ -0,0 +1,35 @@
+name: Test
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+
+jobs:
+  rspec:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        ruby:
+          - '2.6'
+          - '2.7'
+          - '3.0'
+          - '3.1'
+          - '3.2'
+        gemfile:
+          - rails_5
+          - rails_6
+          - rails_7
+    env:
+      BUNDLE_GEMFILE: ${{ github.workspace }}/gemfiles/${{ matrix.gemfile }}.gemfile
+    steps:
+    - uses: actions/checkout@v4
+    - name: Set up Ruby
+      uses: ruby/setup-ruby@v1
+      with:
+        ruby-version: ${{ matrix.ruby }}
+        bundler-cache: true
+    - name: Run RSpec
+      run: bundle exec rspec