install_package "jruby-1.7.5" "http://jruby.org.s3.amazonaws.com/downloads/1.7.5/jruby-bin-1.7.5.tar.gz#9ebd082cf9f29697c76e503e00b79d30e3e9b87071afb8823c3b8b033f5f5723" jruby