Devise token auth not returning the access token and client

here is the reference to stackoverflow
http://stackoverflow.com/questions/37887389/devise-auth-sign-in-api-not-returning-access-token-and-client

I am not able to receive the access token and client in auth/sign_in api
given by devise_token_auth gem

My app was working properly before integrating the omniauth gem. The
issue started coming after integrating the omniauth gem.

session_store.rb

Rails.application.config.session_store :active_record_store, key:
'_my-app_session'

Application controller.rb

class ApplicationController < ActionController::Base
  include DeviseTokenAuth::Concerns::SetUserByToken
  layout false
  before_filter :configure_permitted_parameters, if: :devise_controller?
  before_filter :load_client
  protect_from_forgery with: :null_session, if: Proc.new { |c|
c.request.format == 'application/json' }
  skip_before_filter :verify_authenticity_token, :if => Proc.new { |c|
c.request.format == 'application/json' }
  helper_method :current_user

devise_token_auth version 0.1.30
rails version 4.1.8