def output
      o = if @output.nil?
            './lib/steamd'
          else
            @output
          end

      raise 'output must be a directory' unless File.directory?(o)
      File.expand_path(o)
    end
def output
      o = if @output.nil?
            './lib/steamd'
          else
            @output
          end

      raise 'output must be a directory' unless File.directory?(o)
      File.expand_path(o)
    end
Returns the absolute path of the output directory specified by the
 cli.

 Throws an exception if the output is not a directory

 @example Getting the output path
   opts = CliOptions.new(output: '/some/dir')
   opts.output # => '/some/dir'