I'm trying to get going with submitting a pull request but can't get the tests to run.

My environment:
ruby 1.9.3
rubygems 1.8.15

gems:
bacon (1.1.0)
bundler (1.0.22)
test-spec (0.10.0)
test-unit (2.4.7)
ZenTest (4.6.2)

Before I jump in too far, I want to make sure the test suite runs correctly. I run `rake test` , `rake spec`, `rake fulltest` and `specrb -Ilib:test -a -w` and all fail with the following output:

/usr/local/rvm/gems/ruby-1.9.3-p0@rack-contrib/gems/test-spec-0.10.0/lib/test/spec.rb:12:in `<class:AutoRunner>': uninitialized constant Test::Unit::AutoRunner::RUNNERS (NameError)
from /usr/local/rvm/gems/ruby-1.9.3-p0@rack-contrib/gems/test-spec-0.10.0/lib/test/spec.rb:11:in `<top (required)>'
from /usr/local/rvm/rubies/ruby-1.9.3-p0/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:36:in `require'
from /usr/local/rvm/rubies/ruby-1.9.3-p0/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:36:in `require'
from /usr/local/rvm/gems/ruby-1.9.3-p0@rack-contrib/gems/test-spec-0.10.0/bin/specrb:101:in `<top (required)>'
from /usr/local/rvm/gems/ruby-1.9.3-p0@rack-contrib/bin/specrb:19:in `load'
from /usr/local/rvm/gems/ruby-1.9.3-p0@rack-contrib/bin/specrb:19:in `<main>'

Any help to get started would be appreciated. I'll be happy to submit another patch to the README with whatever feedback I get.