rvm

rvm is ruby version manager. Allow you to have multiple ruby version.

To install rvm, run

gpg --keyserver hkp://keys.gnupg.net --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3
curl -sSL https://get.rvm.io | bash -s stable

To install a ruby version, run

rvm install 2.4.2

To set it default, use

rvm --default use 2.4.2