Allow configuration of callback host from Rails controller

[AMHOL]

Intention

Allow for configuration of a custom callback host from Rails controller, this means we can decouple the handler methods from the controller.

Usage

class MyCustomCallbackHost
  def handle_hard_bounce(payload)
    # Do stuff with payload
  end
end

module Mandrill
  module Webhooks
    class InboxController < ApplicationController
      include Mandrill::Rails::WebHookProcessor

      ignore_unhandled_events!
      authenticate_with_mandrill_keys! 'YOUR_MANDRILL_WEBHOOK_KEY'
      callback_host(MyCustomCallbackHost.new)
    end
  end
end