If you want to use this package as your default system ruby, as root
create symbolic links like so (overwriting any previous default):
 ln -sf /usr/local/bin/ruby25 /usr/local/bin/ruby
 ln -sf /usr/local/bin/erb25 /usr/local/bin/erb
 ln -sf /usr/local/bin/irb25 /usr/local/bin/irb
 ln -sf /usr/local/bin/rdoc25 /usr/local/bin/rdoc
 ln -sf /usr/local/bin/ri25 /usr/local/bin/ri
 ln -sf /usr/local/bin/rake25 /usr/local/bin/rake
 ln -sf /usr/local/bin/gem25 /usr/local/bin/gem
