Create a graph of all defined Classes (A Ruby Script)

i wanted to see ruby classes and each class connected to its parent i used the ruby-graphviz, it turns out that there is another gme named graphviz and it is not the one tha will work correctly. my method was fairly easy, i get all defined constants then filter them to get classes names only, after that i add a node for each class, then iterated on them to add edges between every class and its parent, and then i saved graph as png and pdf, an output example looks like this http://imgur.com/Z1LfLn1

Full script with docs : https://github.com/blazeeboy/RubyScripts/tree/master/2014-4-28