message: update doc for tf.train.Saver() max_to_keep argument to resolve
diff: @@ -1134,7 +1134,8 @@ class Saver(object):
  * `max_to_keep` indicates the maximum number of recent checkpoint files to
  keep. As new files are created, older files are deleted. If None or 0,
  - all checkpoint files are kept. Defaults to 5 (that is, the 5 most recent
  + no checkpoints are deleted from the filesystem but only the last one is
  + kept in the `checkpoint` file. Defaults to 5 (that is, the 5 most recent
  checkpoint files are kept.)
  * `keep_checkpoint_every_n_hours`: In addition to keeping the most recent
  