Removed bob.ip.mtcnn, bob.bio.caffe_face and bob.ip.caffe_extractor [skip ci]

@tiago.pereira this commit has broken bob.pad.face

So, are we going to drop these dependencies with caffe once and for all?

ping @heusch @ageorge

I even archived the projects bob.ip.mtcnn, bob.ip.caffe_extractor and bob.bio.caffe_face

As mentioned somewhere already, bob.ip.mtcnn is not a hard requirement for bob.pad.face, so that should not be a problem to archive it. I'm currently updating bob.pad.face to see if this would be ok (bob.pad.face!100 (merged))

@ageorge A little warning though: the way you are using FaceCropAlign.py won't be available anymore. This is a good opportunity to get rid of that and implement something cleaner ...

@heusch I once tried to use the extractor from bob.ip.tensorflow_extractor, its here https://gitlab.idiap.ch/bob/bob.pad.face/blob/mtcnn/bob/pad/face/preprocessor/FaceCropAlign.py#L168

Well, what I meant is that it would be a good occasion to get rid of FaceCropAlign.py altogether (for a lot of reasons, see bob.pad.face#30 (closed) for instance)

Anyway, glad if you find a way not to use bob.ip.mtcnn !