Add face age gender demo

[tae898]

This is a face detection, recognition, age/gender estimation demo.

I wanted to put this in run_chat.py or run_demo_multidomain.py but I thought first
I make this separate file as a demo, and then when I get enough feedback, I'll try to merge with
run_chat.py or run_demo_multidomain.py.

First install the required packages in ../requirements_face_age_gender.txt,
and then run python run_face_age_gender.py

In order to match the face, this script uses the pre-defined faces in the
directory ./embeddings. At the moment, I'm the only one there. If you want
your faces to be recognized, please send me five photos as in
https://photos.app.goo.gl/LzehxftJVV8M2s1V6

[mxschmdt]

That looks pretty interesting.
Is it possible to provide a script to locally generate the embeddings from the photos? That way we wouldn't have to upload any photos/embeddings and everyone could decide on their privacy.

[tae898]

Yeah you don't have to upload photos/embeddings. Everything is done on your local machine anyways. I just wanted your photos to make the machine "aware" of your existence.

I'll make the code more readable and update the PR.

[tae898]

This will be updated.