Use Redis service in Github, not manual compose

.github/workflows/pr-checks.yml

@@ -9,6 +9,16 @@ jobs:
     strategy:
       matrix:
         ruby-version: ['3.1', '3.0', '2.7']
+    services:
+      redis:
+        image: redis
+        ports:
+          - 22379:6379
+        options: >-
+          --health-cmd "redis-cli ping"
+          --health-interval 5s
+          --health-timeout 5s
+          --health-retries 5
     steps:
       - name: Checkout repo
         uses: actions/checkout@v2
@@ -19,11 +29,7 @@ jobs:
         with:
           ruby-version: ${{ matrix.ruby-version }}
           bundler-cache: true
-      - name: Start backing services
-        run: docker-compose up -d
       - name: Run rubocop
         run: bundle exec rubocop
-      - name: Wait for services to come up
-        run: sleep 3
       - name: Run specs
         run: bundle exec rspec spec/