Use Orion exp name as MLFlow name - when using Orion (instead of the trial name)

[mirkobronzi]

In main.py, change bold into italic:

hyper_params = load_config(args.config)
# Done ASAP, otherwise mlflow will not log with the proper exp. name.
**mlflow.set_experiment(hyper_params['experiment_name'])**
_if orion.client.cli.IS_ORION_ON:
    exp_name = os.getenv('ORION_EXPERIMENT_NAME', 'orion_exp')
else:
    exp_name = hyper_params['experiment_name']
mlflow.set_experiment(exp_name)_
if os.path.exists(os.path.join(args.output, STAT_FILE_NAME)):
    _, _, _, mlflow_run_id = load_stats(args.output)

[mirkobronzi]

solved in #21