Redco version 0.4.15. Updated ckpt saving & loading.
0.4.14
Redco version 0.4.14. Updated SLURM setting. See [language_modeling](https://github.com/tanyuqian/redco/tree/master/examples/language_modeling#under-slurm) or [text_to_text](https://github.com/tanyuqian/redco/tree/master/examples/text_to_text#under-slurm) for detailed use cases.