Add specs for editor in nested resources

spec/dummy/app/admin/posts.rb

@@ -25,6 +25,14 @@ ActiveAdmin.register Post do
       row :tags
       row :created_at
       row :updated_at
+      row :images do |resurce|
+        resurce.images.each do |image|
+          div do
+            link_to image.filename, image, target: '_blank'
+          end
+        end
+        nil
+      end
     end
     active_admin_comments
   end