use pre-trained nets

[rrichards7]

Use pre-trained InceptionResNet for training

see:

1. https://www.kaggle.com/nikhilroxtomar/pretrained-inceptionresnetv2-lb-0-390
2. https://www.kaggle.com/iluxave/inceptionv3-with-sliding-window-image-breakdown (sliding window)
3. https://www.kaggle.com/byrachonok/pretrained-inceptionresnetv2-base-classifier
4. https://www.kaggle.com/wordroid/inceptionresnetv2-resize256-f1loss-lb0-419

other:
https://keras.io/applications/#resnet