Redo python shim script in ruby

Library/ENV/4.3/python

-#!/bin/sh
+#!/System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/bin/ruby -W0
 
-export PATH=$USER_PATH
-exec $(basename $0) $@
+ENV['PATH'] = ENV['USER_PATH']
+exec File.basename($0), *ARGV