Merge branch 'updates' into 'master'

bob/learn/tensorflow/loss/BaseLoss.py

bob/learn/tensorflow/loss/ContrastiveLoss.py

bob/learn/tensorflow/network/Chopra.py

bob/learn/tensorflow/network/Dummy.py

bob/learn/tensorflow/network/InceptionResnetV2.py

bob/learn/tensorflow/network/LightCNN29.py

bob/learn/tensorflow/network/LightCNN9.py

bob/learn/tensorflow/network/__init__.py

bob/learn/tensorflow/network/utils.py

bob/learn/tensorflow/script/compute_statistics.py

bob/learn/tensorflow/test/test_cnn.py

bob/learn/tensorflow/test/test_cnn_prefetch.py

bob/learn/tensorflow/test/test_cnn_pretrained_model.py

bob/learn/tensorflow/test/test_cnn_scratch.py

bob/learn/tensorflow/trainers/Trainer.py