Devise Invitable fails by calling `will_save_change_to_email?` over user

[vovimayhem]

The workaround is:

class User < Authegy::User
  devise :invitable, :database_authenticatable, :registerable,
         :recoverable, :rememberable, :validatable

  # TODO: Fix this on authegy:
  delegate :will_save_change_to_email?, to: :person
end