Sending Devise emails via Sidekiq (or any other job scheduler)

# File: user.rb
class User
  # …
  # Devise overrides
  def send_on_create_confirmation_instructions
    Devise::Mailer.delay_for(1.day).confirmation_instructions(self)
  end

  def send_reset_password_instructions
    Devise::Mailer.delay.reset_password_instructions(self)
  end

  def send_unlock_instructions
    Devise::Mailer.delay.unlock_instructions(self)
  end
end