Extend Quantum Edward so that it does GAN

[rrtucci]

Dustin Tran's Edward uses Black Box Variational Inference BBVI on neural networks to do classification. Can BBVI also be used to do GAN (Generative Adversarial Networks) ? Yes, see https://arxiv.org/abs/1804.03429

Can this be generalized to quantum mechanics, i.e. can one use BBVI to do classification and GAN on a quantum computer? Probably yes. Quantum Edward already does classification. It should be possible to extend the techniques already in use in Quantum Edward so as to do GAN too.