testing devise with shoulda and machinist - ruby-on-rails

Question

I´d like to test my app with shoulda and machinist. I use the devise authentification gem.
I get following error:
$ ruby unit/page_test.rb
c:/Ruby/lib/ruby/gems/1.8/gems/rails-2.3.5/lib/rails/gem_dependency.rb:119:Warning: Gem::Dependency#version_requirements is deprecated and will be rem
oved on or after August 2010. Use #requirement
c:/Ruby/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/dependencies.rb:443:in `load_missing_constant': uninitialized constant Admins (N
ameError)
from c:/Ruby/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/dependencies.rb:80:in `const_missing'
from c:/Ruby/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/dependencies.rb:92:in `const_missing'
from c:/Users/Mattherick/Desktop/heimspiel/heimspiel_app/app/controllers/admins_controller.rb:1
from c:/Ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require'
from c:/Ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'
from c:/Ruby/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/dependencies.rb:158:in `require'
from c:/Ruby/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/dependencies.rb:265:in `require_or_load'
from c:/Ruby/lib/ruby/gems/1.8/gems/activesupport-2.3.5/lib/active_support/dependencies.rb:224:in `depend_on'
... 12 levels...
from ./unit/../test_helper.rb:2
from c:/Ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require'
from c:/Ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'
from unit/page_test.rb:1
Somebody an idea what´s wrong? If I don´t use devise my tests are okay.
And my second question: Does somebdoy has a good tutorial for increasing different roles in the devise gem? If I generate my own views and add a few attributes to my devise-model, they won´t be save in the database. I read the docu at github, but don´t really checked it.
mattherick