Acquisition function API redesign (#447)

* Redesign the acquisition function API

* Add async optimization w/ kriging believer example

* Use `typing.Union` instead of `|`

* Add ConstantLiar, fix bugs, reran code

* Fix typo

* Slight changes, add many tests

* Add `base_acq` `ThompsonSampling`, fix a bug in `KrigingBeliever`

* Clean code, add docstrings

* add tests, rm kriging believer, dont use gp hedge as default

* Use `self.base_acq` instead of supplying it as an argument to `._get_acq`

* Add special exceptions covering too few registered points

* Notebook to showcase acquisition functions

* Linting, code style

* Drop references to believer from script

* Delete deprecated parameters from `suggest`

* Use `abc.ABC` for acquisition base class

* Add more tests

* Fix type signature breaking Python 3.9

* Trigger CI

* Clean docstring

Author: till-m

bayes_opt/__init__.py

@@ -1,20 +1,19 @@
 """Pure Python implementation of bayesian global optimization with gaussian processes."""
 from .bayesian_optimization import BayesianOptimization, Events
-from .domain_reduction import SequentialDomainReductionTransformer
-from .util import UtilityFunction
+from .domain_reduction import SequentialDomainReductionTransformer 
 from .logger import ScreenLogger, JSONLogger
 from .constraint import ConstraintModel
-from .util import UtilityFunction
+from . import acquisition
 
 import importlib.metadata
 __version__ = importlib.metadata.version('bayesian-optimization')
 
 
 
 __all__ = [
+    "acquisition",
     "BayesianOptimization",
     "ConstraintModel",
-    "UtilityFunction",
     "Events",
     "ScreenLogger",
     "JSONLogger",