Rails LinkedIn Ошибка входа

Question

Я пытался понять, как решить эту проблему часами, и не могу. Я продолжаю получать эту ошибку:

Невозможно загрузить константу OmniauthCallbacksController, ожидается, что /Users/omar.amiri/Desktop/rails-devise-roles/app/controllers/omniauth_callbacks_controller.rb определит ее

omniauth_callbacks_controller.rb

class OmniauthCallbacksController < Devise::OmniauthCallbacksController   

def linkedin
    auth = env["omniauth.auth"]
    @user = User.connect_to_linkedin(request.env["omniauth.auth"],current_user)
    if @user.persisted?
      flash[:notice] = I18n.t "devise.omniauth_callbacks.success"
      sign_in_and_redirect @user, :event => :authentication
    else
      session["devise.linkedin_uid"] = request.env["omniauth.auth"]
      redirect_to new_user_registration_url
    end

  end

end

user.rb.rb

class User < ActiveRecord::Base
  # Include default devise modules. Others available are:
  # :confirmable, :lockable, :timeoutable and :omniauthable
  devise :database_authenticatable, :registerable,
         :recoverable, :rememberable, :trackable, :validatable, :omniauthable

  def self.connect_to_linkedin(auth, signed_in_resource=nil)
    user = User.where(:provider => auth.provider, :uid => auth.uid).first
    if user
      return user
    else
      registered_user = User.where(:email => auth.info.email).first
      if registered_user
        return registered_user
      else

        user = User.create(name:auth.info.first_name,
                            provider:auth.provider,
                            uid:auth.uid,
                            email:auth.info.email,
                            password:Devise.friendly_token[0,20],
                          )
      end

    end
  end   

end

routes.rb

Rails.application.routes.draw do
  root to: 'visitors#index'
  devise_for :users, :controllers => { :omniauth_callbacks => "omniauth_callbacks" }
  resources :users
end