Fix spacing
Better handling of default extension
Use environment ruby
Rename 'x' to the more semantic 'file'
More succint/clear next clause in recursion method
Use the File class' directory? method to check for directories
Fix require statements
Remove unnecessary argument from calculate_dirs method
Move file parsing into separate method
Restructure calculate_dirs to be more clear/concise
Fix instance variable name
Move test directory into setup method
Better handling of extensions
Restructure tests to be system independent