Added the command to symlink bin/jruby to bin/ruby (issue #21).
Added the command to symlink bin/jruby to bin/ruby (issue #21).

JeanMertz/chruby-fish,postmodern/chruby,kbrock/chruby,JeanMertz/chruby-fish,postmodern/chruby,ilikepi/chruby,regularfry/chruby,eunomie/chgo,ilikepi/chruby,ngpestelos/chruby,ngpestelos/chruby,regularfry/chruby,eunomie/chgo,rstacruz/chruby-fish,kbrock/chruby,rstacruz/chruby-fish