TypeError: load() missing 1 required positional argument: 'Loader' in main branch

[xuehui1991]

When I use the command "python run_atari_game.py --config examples/configs/maatari/dqn_basketball_pong.yaml " to setup the atari in examples. will raise an error:

Traceback (most recent call last):
  File "run_atari_game.py", line 26, in <module>
    config = yaml.load(f)
TypeError: load() missing 1 required positional argument: 'Loader'