Add an integration test for roles

Add an app with roles to the integration tests. We'll deploy two web
containers and one worker. The worker just sleeps, so we are testing
that the container has booted.

test/integration/main_test.rb

@@ -42,6 +42,22 @@ class MainTest < IntegrationTest
     assert_no_remote_env_file
   end
 
+  test "app with roles" do
+    @app = "app_with_roles"
+
+    kamal :envify
+
+    version = latest_app_version
+
+    assert_app_is_down
+
+    kamal :deploy
+
+    assert_app_is_up version: version
+    assert_hooks_ran "pre-connect", "pre-build", "pre-deploy", "post-deploy"
+    assert_container_running host: :vm3, name: "app-workers-#{version}"
+  end
+
   test "config" do
     config = YAML.load(kamal(:config, capture: true))
     version = latest_app_version
@@ -115,4 +131,8 @@ class MainTest < IntegrationTest
       assert vm1_image_ids.any?
       assert vm1_container_ids.any?
     end
+
+    def assert_container_running(host:, name:)
+      assert docker_compose("exec #{host} docker ps --filter=name=#{name} -q", capture: true).strip.present?
+    end
 end