SM not supporting Rails 3

gistfile1.rb

## Gemfile

# and rake tasks are available in development mode:
group :test do
  gem "sample_models"
end


## unit test
require 'test_helper'

class ProjectTest < ActiveSupport::TestCase
  test "total_time gives the total time from all of the project's tasks" do
    t1 = Task.sample(:minutes => 60)
  end
end



## e-ror

/Users/franklakatos/.rvm/gems/ruby-1.9.2-head/gems/sample_models-1.0.0/lib/sample_models/creation.rb:51:in `<class:Creation>': uninitialized constant SampleModels::Creation::HashWithIndifferentAccess (NameError)
	from /Users/franklakatos/.rvm/gems/ruby-1.9.2-head/gems/sample_models-1.0.0/lib/sample_models/creation.rb:2:in `<module:SampleModels>'
	from /Users/franklakatos/.rvm/gems/ruby-1.9.2-head/gems/sample_models-1.0.0/lib/sample_models/creation.rb:1:in `<top (required)>'
	from /Users/franklakatos/.rvm/gems/ruby-1.9.2-head/gems/sample_models-1.0.0/lib/sample_models.rb:3:in `require'
	from /Users/franklakatos/.rvm/gems/ruby-1.9.2-head/gems/sample_models-1.0.0/lib/sample_models.rb:3:in `<top (required)>'
	from /Users/franklakatos/.rvm/gems/ruby-1.9.2-head/gems/bundler-1.0.0.rc.1/lib/bundler/runtime.rb:64:in `require'
	from /Users/franklakatos/.rvm/gems/ruby-1.9.2-head/gems/bundler-1.0.0.rc.1/lib/bundler/runtime.rb:64:in `block (2 levels) in require'
	from /Users/franklakatos/.rvm/gems/ruby-1.9.2-head/gems/bundler-1.0.0.rc.1/lib/bundler/runtime.rb:62:in `each'
	from /Users/franklakatos/.rvm/gems/ruby-1.9.2-head/gems/bundler-1.0.0.rc.1/lib/bundler/runtime.rb:62:in `block in require'
	from /Users/franklakatos/.rvm/gems/ruby-1.9.2-head/gems/bundler-1.0.0.rc.1/lib/bundler/runtime.rb:51:in `each'
	from /Users/franklakatos/.rvm/gems/ruby-1.9.2-head/gems/bundler-1.0.0.rc.1/lib/bundler/runtime.rb:51:in `require'
	from /Users/franklakatos/.rvm/gems/ruby-1.9.2-head/gems/bundler-1.0.0.rc.1/lib/bundler.rb:109:in `require'
	from /Users/franklakatos/Sites/kludge/config/application.rb:7:in `<top (required)>'
	from /Users/franklakatos/Sites/kludge/config/environment.rb:2:in `require'
	from /Users/franklakatos/Sites/kludge/config/environment.rb:2:in `<top (required)>'
	from /Users/franklakatos/Sites/kludge/test/test_helper.rb:2:in `require'
	from /Users/franklakatos/Sites/kludge/test/test_helper.rb:2:in `<top (required)>'
	from test/unit/project_test.rb:1:in `require'
	from test/unit/project_test.rb:1:in `<top (required)>'
	from /Users/franklakatos/.rvm/gems/ruby-1.9.2-head/gems/rake-0.8.7/lib/rake/rake_test_loader.rb:5:in `load'
	from /Users/franklakatos/.rvm/gems/ruby-1.9.2-head/gems/rake-0.8.7/lib/rake/rake_test_loader.rb:5:in `block in <main>'
	from /Users/franklakatos/.rvm/gems/ruby-1.9.2-head/gems/rake-0.8.7/lib/rake/rake_test_loader.rb:5:in `each'
	from /Users/franklakatos/.rvm/gems/ruby-1.9.2-head/gems/rake-0.8.7/lib/rake/rake_test_loader.rb:5:in `<main>'
Errors running test:units!