[fix] missing template because "render nothing: true" is removed in Rails 5.1
[fix] missing template because "render nothing: true" is removed in Rails 5.1

ShinjiTanimoto/shirasagi,sunny4381/shirasagi,itowtips/shirasagi,shirasagi/shirasagi,ShinjiTanimoto/shirasagi,MasakiInaya/shirasagi,shirasagi/ss-handson,itowtips/shirasagi,itowtips/shirasagi,itowtips/shirasagi,MasakiInaya/shirasagi,MasakiInaya/shirasagi,tany/ss,MasakiInaya/shirasagi,shirasagi/shirasagi,mizoki/shirasagi,shirasagi/shirasagi,sunny4381/shirasagi,tany/ss,shirasagi/ss-handson,shirasagi/shirasagi,mizoki/shirasagi,mizoki/shirasagi,tany/ss,shirasagi/ss-handson,sunny4381/shirasagi,ShinjiTanimoto/shirasagi,shirasagi/ss-handson,sunny4381/shirasagi,tany/ss,mizoki/shirasagi,ShinjiTanimoto/shirasagi