incompatible with newer versions of bayesian_optimization

[gauravmanmode]

Issue Description

bayesian_optimization==1.4.0 is pinned strictly in requirements/main.txt
Trying to install newer versions of bayesian_optimization>=1.4.0 and nevergrad>1.0.3 causes conflict issues.

Problem

nevergrad imports UtilityFunction and BayesianOptimization which are now deprecated in newer versions of bayesian_optimization.

Ideas

A good solution would be to upgrade to use acquisition function instead.