Merge branch 'cross_validation' into 'master'

bob/learn/pytorch/architectures/FASNet.py

bob/learn/pytorch/architectures/MCCNN.py

bob/learn/pytorch/config/mccnn/wmca_mccnn_cv.py

bob/learn/pytorch/extractor/image/FASNet.py

bob/learn/pytorch/extractor/image/__init__.py

bob/learn/pytorch/scripts/train_fasnet.py

bob/learn/pytorch/scripts/train_mccnn.py

bob/learn/pytorch/test/test.py

bob/learn/pytorch/trainers/FASNetTrainer.py

bob/learn/pytorch/trainers/MCCNNTrainer.py

bob/learn/pytorch/trainers/__init__.py

doc/guide_mccnn_pad.rst

setup.py