def mkpath(*args)
      args[0] = {} unless args[0]
      args[0] = args[0].merge(mode: 0700) unless args[0][:mode]
      FileUtils.mkpath(self.to_s, *args)
    end
def mkpath(*args)
      args[0] = {} unless args[0]
      args[0] = args[0].merge(mode: 0700) unless args[0][:mode]
      FileUtils.mkpath(self.to_s, *args)
    end
Make paths with permission 0700 by defautl. Otherwise, this is same as
 Pathname#mkpath.