Merge pull request #728 from ruby/move-test-directory

Use test/rdoc instead of test directory.

Author: hsbt

Rakefile

@@ -35,7 +35,7 @@ task ghpages: :rdoc do
 end
 
 Rake::TestTask.new(:test) do |t|
-  t.libs << "test"
+  t.libs << "test/rdoc"
   t.verbose = true
   t.test_files = FileList['test/**/test_*.rb']
 end