IRIS agent in Hugging face transformers

[RUFFY-369]

Hi folks @eloialonso @vmicheli ,

First of all, a brilliant paper and I had great fun going through and forth the text and especially the code, every nitty-gritty. Inspired by the results, I decided to perform a little contribution to port the IRIS agent into Hugging face transformers library.

Here is the tutorial for training ported IRIS agent with Hugging face trainer: https://github.com/RUFFY-369/Transformers-tutorials/blob/main/IRIS/train_Iris_agent_on_atari.ipynb

Cheers!