Best hyperparameters script

[kylebgorman]

Yoyodyne's W&B examples includes a script called best_hyperparameters.py which retrieves the best hyperparameters from a W&B sweep (using the API, it's pretty easy) and then returns then as a list of flags. The API makes this pretty easy; the only tricky thing is some things appear multiple times due to the linking between datamodule and model, and some things are just defaults.

This is very doable for UDTube too, but instead it should generate a YAML config file.

I am self-assigning because this is easy.