undefined method `use_transactional_fixtures='

gistfile1.txt

#twitter という名前のgem(http://twitter.rubyforge.org/)の
#サンプルアプリ(https://github.com/jnunemaker/twitter-app/)を動かそうとしているんだけど、
#rake test:units したところ、undefined method `use_transactional_fixtures='
#というエラーが出てハマっている。
#あと、database.ymlがない。

user0@user0-desktop:~/dev/ruby/tmp/twitter-app$ rake test:units
(in /home/user0/dev/ruby/tmp/twitter-app)
/usr/bin/ruby1.8 -I"lib:test" "/home/user0/.rvm/gems/ruby-1.8.7-p302@r2/gems/rake-0.8.7/lib/rake/rake_test_loader.rb" "test/unit/helpers/statuses_helper_test.rb" "test/unit/helpers/direct_messages_helper_test.rb" "test/unit/helpers/friendships_helper_test.rb" "test/unit/user_test.rb" 
./test/test_helper.rb:8: undefined method `use_transactional_fixtures=' for ActiveSupport::TestCase:Class (NoMethodError)
	from ./test/unit/helpers/statuses_helper_test.rb:1:in `require'
	from ./test/unit/helpers/statuses_helper_test.rb:1
	from /home/user0/.rvm/gems/ruby-1.8.7-p302@r2/gems/rake-0.8.7/lib/rake/rake_test_loader.rb:5:in `load'
	from /home/user0/.rvm/gems/ruby-1.8.7-p302@r2/gems/rake-0.8.7/lib/rake/rake_test_loader.rb:5
	from /home/user0/.rvm/gems/ruby-1.8.7-p302@r2/gems/rake-0.8.7/lib/rake/rake_test_loader.rb:5:in `each'
	from /home/user0/.rvm/gems/ruby-1.8.7-p302@r2/gems/rake-0.8.7/lib/rake/rake_test_loader.rb:5
rake aborted!
Command failed with status (1): [/usr/bin/ruby1.8 -I"lib:test" "/home/user0...]

#./test/test_helper.rb

ENV["RAILS_ENV"] = "test"
require File.expand_path(File.dirname(__FILE__) + "/../config/environment")
require 'test_help'
require 'matchy'
require 'mocha'

class ActiveSupport::TestCase
  self.use_transactional_fixtures = true　#<=ここでエラーが出ているが、
  self.use_instantiated_fixtures  = false
  fixtures :all
end

#gem list

*** LOCAL GEMS ***

aasm (2.2.0)
abstract (1.0.0)
actionmailer (3.0.0, 2.3.10, 2.3.8, 2.3.5)
actionpack (3.0.0, 2.3.10, 2.3.8, 2.3.5)
activemodel (3.0.0)
activerecord (3.0.0, 2.3.10, 2.3.8, 2.3.5)
activeresource (3.0.0, 2.3.10, 2.3.8, 2.3.5)
activesupport (3.0.0, 2.3.10, 2.3.8, 2.3.5)
arel (1.0.1)
authlogic (2.1.6)
builder (2.1.2)
bundler (1.0.2)
chronic (0.3.0)
configuration (1.1.0)
crack (0.1.8, 0.1.6)
cucumber (0.9.2)
cucumber-rails (0.3.2)
database_cleaner (0.6.0)
diff-lcs (1.1.2)
erubis (2.6.6)
faker (0.3.1)
ffi (0.6.3)
gettext (2.1.0, 1.93.0)
gherkin (2.2.9)
hashie (0.4.0, 0.2.2)
heroku (1.10.14)
httparty (0.6.1, 0.5.2)
i18n (0.4.1)
i18n_generators (1.0.0.pre1)
jeremydurham-restful_authentication (1.1.7)
jnunemaker-matchy (0.4.0)
json (1.4.6)
json_pure (1.4.6)
launchy (0.3.7)
locale (2.0.5)
machinist (1.0.6)
mail (2.2.7)
mime-types (1.16)
mocha (0.9.9)
multi_json (0.0.5)
nokogiri (1.4.3.1)
oauth (0.4.4, 0.3.6)
packet (0.1.15)
polyglot (0.3.1)
postgres-pr (0.6.3)
rack (1.2.1, 1.1.0, 1.0.1)
rack-mount (0.6.13)
rack-test (0.5.6)
rails (2.3.10, 2.3.8, 2.3.5)
railties (3.0.0)
rake (0.8.7)
rest-client (1.6.1)
rspec (2.0.1)
rspec-core (2.0.1)
rspec-expectations (2.0.1)
rspec-mocks (2.0.1)
rspec-rails (2.0.1)
ruby-hmac (0.4.0)
sequel (3.15.0)
sinatra (1.0)
sqlite3-ruby (1.3.1, 1.2.4)
taps (0.3.13)
term-ansicolor (1.0.5)
thor (0.14.3)
thoughtbot-factory_girl (1.2.2, 1.2.0)
thoughtbot-shoulda (2.10.0)
treetop (1.4.8)
twitter (0.9.12, 0.9.1)
tzinfo (0.3.23)
webrat (0.7.2)
yaml_waml (0.3.0)