手順
# rbenvをインストール
# 参考: https://github.com/rbenv/rbenv#basic-github-checkout
git clone https://github.com/rbenv/rbenv.git ~/.rbenv
echo 'export PATH="$HOME/.rbenv/bin:$PATH"' >> ~/.bash_profile
echo 'eval "$(rbenv init -)"' >> ~/.bash_profile
source ~/.bash_profile
# ruby-buildをインストール
# 参考: https://github.com/rbenv/ruby-build#readme
mkdir -p "$(rbenv root)"/plugins
git clone https://github.com/rbenv/ruby-build.git "$(rbenv root)"/plugins/ruby-build