Copy yaml file error while training

[SomarajuHarsha]

When running the train.py model, it tries to copy the config yaml file to the output directory along with timestamp using shutil. But, it does not copy because of ":" in the datetime.

It is in line 98 in train.py. I suggest to change str(datetime.datetime.now())[:19] with str(datetime.datetime.now())[:19].replace(':', '')