recommit all changes

bob/bio/face/annotator/bobiptinyface.py

bob/bio/face/config/baseline/mxnet_pipe.py

bob/bio/face/config/baseline/opencv_pipe.py

bob/bio/face/config/baseline/pytorch_pipe_v1.py

bob/bio/face/extractor/MxNetModel.py

bob/bio/face/extractor/OpenCVModel.py

bob/bio/face/extractor/PyTorchModel.py

bob/bio/face/extractor/TensorFlowModel.py

doc/deeplearningextractor.rst

doc/img/opencv_lfw_pipe.png

doc/implemented.rst

doc/references.rst

requirements.txt