add dependency

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48031 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
add .gitignore

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48032 b2dd03c8-39d4-4d8f-98ff-823fe69b080e