Update README with google colab example

[AndreFCruz]

Hi 👋

Changelog:

• added a Dockerfile that can be used for users on non-linux platforms
  • plus references to this dockerfile in the README
  • test it with docker run -p 8888:8888 ndrcrz/fairgbm-miniconda
• added a new python notebook to be used with google colab
  • added ref to a the colab example notebook in the READMEs
• updated the UCI Adult hpt notebook to be compatible with the latest hyperparameter-tuning package;
  • namely all "equal_odds" metrics were renamed to "equalized_odds"
• updated bibtex citation to match openreview/ICLR official bibtex

By the way, the google colab links are currently pointing to my fork, they can only be properly updated after this is merged.

@sgpjesus can you take a quick look? 👀