ignore MaxPoolGrad re-definition error on new tensorflow

[winston-zillow]

No description provided.

[winston-zillow]

Output on tensorflow 1.2.1

(tf2) ~/3rdparty/maml$ python3 main.py --train=False --datasource=miniimagenet --metatrain_iterations=60000 --meta_batch_size=4 --update_batch_size=5 --update_lr=0.01 --num_updates=5 --num_classes=5 --logdir=logs/miniimagenet5shot/ --num_filters=32 --max_pool=True --stop_grad=True
WARN: Cannot define MaxPoolGrad, likely already defined for this version of tensorflow: "Registering two gradient with name 'MaxPoolGrad' !(Previous registration was in _find_and_load_unlocked <frozen importlib._bootstrap>:958)"
Generating filenames
Generating image processing ops

[cbfinn]

LGTM. Thanks!