Merge branch 'tf2' into 'master'

bob/__init__.py

bob/ip/__init__.py

bob/ip/tensorflow_extractor/DrGanMSU.py

bob/ip/tensorflow_extractor/Extractor.py

bob/ip/tensorflow_extractor/FaceNet.py

bob/ip/tensorflow_extractor/MTCNN.py

bob/ip/tensorflow_extractor/Vgg16.py

bob/ip/tensorflow_extractor/__init__.py

bob/ip/tensorflow_extractor/data/checkpoint

...p/tensorflow_extractor/data/model.ckp.data-00000-of-00001

bob/ip/tensorflow_extractor/data/model.ckp.index

bob/ip/tensorflow_extractor/data/model.ckp.meta

bob/ip/tensorflow_extractor/test.py

doc/conf.py

doc/guide.rst

doc/index.rst

setup.py