Add support/examples for GANs

[zaksemenov]

[zaksemenov]

Feature

It would be nice to see examples/support for how to use stoke with GAN training

Motivation

It is unclear how to train a GAN using stoke and if 2 stoke objects would need to be initialized (for generator and discriminator) or if it could be adapted to fit into a main stoke object

Proposal

Add necessary example for training a simple GAN or extend support if it cannot work out of the box