我已经在我的开发机器上安装了活动管理员,它工作正常。但是当我运行heroku run rake db:migrate它给我以下错误
rake aborted! undefined method `setup' for ActiveAdmin:Module
这是我的宝石文件
source 'https://rubygems.org'
gem 'rails', '3.2.6'
gem 'pg'
gem 'haml'
gem 'haml-rails'
gem 'sorcery'#, "~> 0.7.12"
gem 'jquery-rails'
gem 'localeapp'
# Gems used only for assets and not required
# in production environments by default.
group :assets do
  gem "activeadmin", :git => "git://github.com/gregbell/active_admin.git"
  gem 'sass-rails'#,   '~> 3.2.5'
  gem 'coffee-rails'#, '~> 3.2.2'
  gem 'twitter-bootstrap-rails'
  gem 'uglifier'
end
group :production do
  gem 'thin'
end