def finish(iteration, elapsed_time, reprint)
      file.write("\r" + padded_line(iteration, elapsed_time)) if reprint
      file.write("\n")
      file.flush
    end
def finish(iteration, elapsed_time, reprint)
      file.write("\r" + padded_line(iteration, elapsed_time)) if reprint
      file.write("\n")
      file.flush
    end
Prints a line of text to @file, after deleting the previously printed line

 @param iteration [Integer] number of iterations, out of the total, that are completed
 @param elapsed_time [Float] number of seconds passed since start
 @param reprint [Boolean] do we need to reprint the line one last time?