def mkdir(option={})
      mode = option[:mode] || 0700
      path = create(option)
      path.mkdir(mode)
      return path
    end
def mkdir(option={})
      mode = option[:mode] || 0700
      path = create(option)
      path.mkdir(mode)
      return path
    end
Create a temporary directory.

 @param option [Hash]
 @option option [Integer] :mode
   mode for the directory permission
 @option option [String] :basename
   prefix of directory name
 @option option [Pathname] :basedir
   pathname of base directory