Draft: Feature/metrics

Add of metrics tool.

Add of files:

odeon/commons/metrics/metrics.py odeon/commons/metrics/metrics_binary.py odeon/commons/metrics/metrics_multiclass.py odeon/commons/metrics/metrics_factory.py

odeon/commons/reports/report_binary.py odeon/commons/reports/report_multiclass.py

Items to be examined:

The calculation of the metrics in itself, whether the code is factorable and if it fits well with what you wanted.

To test:

To test the tool, you have to create a json configuration file and launch the code with odeon metrics -c <config.json>. metrics_multiclass_simple.json