Wiki のバージョン管理 (#317) (#333)

#317

#317

#317

#317

#317

#317

Co-authored-by: miteruzo <miteruzo@naver.com>
Reviewed-on: #333

backend/spec/factories/wiki_pages.rb

@@ -3,5 +3,7 @@ FactoryBot.define do
     title { "TestPage" }
     association :created_user, factory: :user
     association :updated_user, factory: :user
+
+    body { ' ' }
   end
 end