style: correct coding style with rubocop linter

config/routes.rb

@@ -42,7 +42,7 @@ Rails.application.routes.draw do
   get "events/:slug.:id/orders/new", to: "orders#new", as: "event_order_new"
   post "events/:slug.:id/orders", to: "orders#create", as: "event_order_create"
 
-  resources :orders, only: [:show] do
+  resources :orders, only: [ :show ] do
     member do
       get :checkout
       post :retry_payment