fails:Dir.delete removes empty directories
fails:Dir.delete calls #to_path on non-String arguments
fails:Dir.delete raises an Errno::ENOTEMPTY when trying to remove a nonempty directory
fails:Dir.delete raises an Errno::ENOENT when trying to remove a non-existing directory
fails:Dir.delete raises an Errno::ENOTDIR when trying to remove a non-directory
fails:Dir.delete raises an Errno::EACCES if lacking adequate permissions to remove the directory
