We should put a  comment that the scorer returns the opposite of the loss function. Or introduce an alias function named `log_likelihood_score(y_true, y_pred)` that returns `- log_loss(y_true, y_pred)`.

I am fine with having both functions as in practice sometimes you want once or the other and that makes the code more readable  to avoid having to throw a `-` in the middle of an expression. We would also increase google-ability by having both as the reference API has a very good page-rank on such keywords apparently.