Change the name of test files and the test helper file to match ruby test file naming conventions
Remove redundant additions to the loadpath

Rake::TestTask automatically adds lib, and test is being added in the Rakefile so the test_helper does not need to add anything to the loadpath.
Remove unnecessary class Test::Unit::TestCase from the test helper

I'm not sure what the purpose of this was meant to be.
Remove unnecessary requiring of rubygems/bundler

I haven't found this to be necessary anymore; rubygems now ships with ruby and everyone uses bundler.
Require minitest/autorun instead of test/unit

Test/unit is just a shim on top of minitest in ruby 1.9 anyway; in my opinion it's better to require minitest.
Use the latest version of minitest rather than the version that comes with ruby
Remove an unnecessary require 'clever-ruby' from the test file; the test_helper takes care of this
Merge pull request #3 from thinkthroughmath/test_cleanup

Test cleanup