Ruby on rails OmniAuth+Rails 3+Cucumber-未定义的方法'test_mode！'对于designe:：OmniAuth:模块（NoMethodError）

在我的新Rails 3.1项目中运行命令“cucumber”时，出现以下错误：

undefined method `test_mode!' for Devise::OmniAuth:Module (NoMethodError)

以下是我的珍宝：

group :development, :test do
  gem 'rspec-rails'
  gem 'turn', '<0.8.3'
  gem 'cucumber', '1.1.4'
  gem 'capybara'
  gem 'database_cleaner'
  gem 'cucumber-rails'
  gem 'launchy'
end

gem 'devise'
gem 'omniauth-facebook'
gem 'omniauth'
gem 'koala'

有人看到这里出了什么问题吗

Devise::OmniAuth.test_mode!

Before do
  Devise::OmniAuth.short_circuit_authorizers!
  Devise::OmniAuth.stub!(:facebook) do |b| 
    b.post('/oauth/access_token') do
      [200, {}, { :access_token => 'facebook_access_token' }.to_json]
    end 

    b.get('/me?access_token=facebook_access_token') do
      [   
        200, {}, 
        {   
          :id         => '1111111111',
          :link       => 'http://facebook.com/username',
          :email      => 'username@example.com',
          :first_name => 'User',
          :last_name  => 'Name',
          :website    => 'http://relike.com/users/username'
        }.to_json
      ]   
    end 
  end 
end