# File lib/homesick/utils.rb, line 102
    def subdir_add(castle, path)
      subdir_filepath = subdir_file(castle)
      File.open(subdir_filepath, 'a+') do |subdir|
        subdir.puts path unless subdir.readlines.reduce(false) do |memo, line|
          line.eql?("#{path}\n") || memo
        end
      end

      inside castle_dir(castle) do
        git_add subdir_filepath
      end
    end