Add an Actions workflow

After 14 years with Travis it's time to move to Actions.

.github/workflows/ci.yml

@@ -0,0 +1,42 @@
+name: CI
+
+on:
+  push:
+    branches:
+      - "main"
+  pull_request:
+    branches:
+      - "main"
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        ruby-version:
+          - "3.4.2"
+          - "3.3.7"
+          - "3.2.7"
+
+    services:
+      rabbitmq:
+        image: rabbitmq:4-management
+        ports:
+          - 15672:15672
+          - 5672:5672
+
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up Ruby ${{ matrix.ruby-version }}
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: ${{ matrix.ruby-version }}
+      - name: Install dependencies
+        run: bundle install
+
+      - name: Configure RabbitMQ
+        run: BUNNY_RABBITMQCTL=DOCKER:${{job.services.rabbitmq.id}} BUNNY_RABBITMQ_PLUGINS=DOCKER:${{job.services.rabbitmq.id}} bin/ci/before_build.sh
+
+      - name: Run tests
+        run: bundle exec rspec -c