Compare metrics between experiments/ runs

[SdgJlbl]

Building up on feature https://github.com/peopledoc/ml-versioning-tools/issues/48, we want to compare metrics between experiments (git branches). For example, MLV-tools could produce a table of hyperparameters / input data and output metrics in the form of a CSV file. If there are some stochasticity in the experiment, we want to compare metrics between runs too.