the gpt example is broken

[AlexanderChen1989]

<bmcook.trainer.CookOutput object at 0x7f19f999a160>
<bmcook.trainer.CookOutput object at 0x7f8bc225ba60>
Traceback (most recent call last):
File "gpt2_test.py", line 186, in
Traceback (most recent call last):
File "gpt2_test.py", line 186, in
main()
File "gpt2_test.py", line 142, in main
if outputs.lag_loss != 0:
AttributeError: 'CookOutput' object has no attribute 'lag_loss'
main()
File "gpt2_test.py", line 142, in main
if outputs.lag_loss != 0:
AttributeError: 'CookOutput' object has no attribute 'lag_loss'