Starting with Rails 5.1:

- message: password_changed is not an attribute known to Active Record. This behavior
    is deprecated and will be removed in the next version of Rails. If you'd like
    password_changed to be managed by Active Record, add `attribute :password_changed
    to your class.
  callstack: app/models/image.rb:31:in `set_password_changed'
- message: password_changed is not an attribute known to Active Record. This behavior
    is deprecated and will be removed in the next version of Rails. If you'd like
    password_changed to be managed by Active Record, add `attribute :password_changed
    to your class.
  callstack: app/models/user.rb:527:in `set_password_changed'