Zip file is now reset

There was an [issue](https://github.com/neo/ruby_koans/issues/115) that someone raised a while back that when they downloaded the zip file from the [main site](http://rubykoans.com/), some of the ruby koans were already completed. 

This pull requests fixes that. Now when you unzip the file, and run `ruby path_to_enlightenment.rb`, you start at the very beginning.