- Add command lines example for stage 3;
- Add experiment_id option that is useful sometimes;
- Fix subsets_used param;
- Remove experiment_id in config experiment file names;
- Add config experiment files for stages 2 and 3;
- Add results for stages 2 and 3 (california_housing).

- Add a TODO for the subset in train
- Remove an useless new line

- Fix bug of resolve_experiment_id after 10 exp ids;
- Display the new experiment id at the beginning of the training;
- For now there's only a simple losses plot in compute_results.

rassemble le code dans un répertoire 'code' + update setup.py en conséquence + ajoute scikit-learn à requirements.txt

- Add error handling module (TODO: add logging over the code)
- Record dataset parameters and model parameters
- Begin compute_results, plotter and visualize files