[rspec-users] rspec 2 - undefined method `redirect_to?' for #<Rack::MockResponse:0xa43ef14>

[oren]

I try to test sinatra app using rspec 2.0.0 and rack-test 0.5.6

  it "redirect non-authenticated user to logout page" do
    get '/'
    last_response.should be_redirect_to('/login)
  end

and I get:
undefined method `redirect_to?' for #<Rack::MockResponse:0xa43ef14>


where can I find reference/guide for methods I can use in rspec 2?
I think it might be here, but I am not sure where:
http://github.com/rspec/rspec
http://github.com/rspec/rspec-core

Thanks!