yum install -y openssl-devel readline-devel zlib-devel
git clone https://github.com/tagomoris/xbuild.git
./xbuild/ruby-install 2.1.1 /opt/ruby-2.1
echo 'export PATH=/opt/ruby-2.1/bin:$PATH' > /etc/profile.d/ruby.sh
visudo
-Defaults secure_path = /sbin:/bin:/usr/sbin:/usr/bin
+Defaults secure_path = /sbin:/bin:/usr/sbin:/usr/bin:/opt/ruby-2.1/bin