以下はこれを前提に
curl -sSL https://rvm.io/mpapis.asc | gpg --import - curl -sSL https://rvm.io/pkuczynski.asc | gpg --import - curl -sSL https://get.rvm.io | sudo bash -s stable rvm reload
rvm install x.y.z rvm use x.y.z --default
gem install bunlder gem install rails