Errors in mario_ppo.py

[sequtan]

Errors in mario_ppo.py. Fix please:

mario_ppo.py:174: RuntimeWarning: invalid value encountered in greater
return (p.cumsum(axis=axis) > r).argmax(axis=axis)

Traceback (most recent call last):
File "mario_ppo.py", line 413, in
rewards = np.hstack(rewards) * reward_scale
NameError: name 'reward_scale' is not defined