我正在使用Rails5.0.0.beta3并创建一个rails-api。当我运行时rails-apigeneratescaffolduseremail:stringpassword:stringauth_token:string显示错误.rvm/gems/ruby-2.2.3/gems/bundler-1.11.2/lib/bundler/runtime.rb:80:in`rescueinblock(2levels)inrequire':Therewasanerrorwhiletryingtoloadthegem'rails-api'.(Bundler::GemRequireError