ActionController::HideActions does not exist in Rails 5

ActionController::HideActions will be removed from Rails 5, see rails/rails#18336. Rails developers recommend to use 'private' instead 'hide_action'. So Rails 5 does not work with current version. See two ways to fix it:
1. remove ActionController::HideActions 
2. remove ActionController::HideActions for Rails 5, and keep for another versions

What do you think? Ready to make related pr. 
