18.2.0
Move test helpers into an utils module
T325 weakref with slots (#420)
Consistently use "base class" and "subclass" (#436)
Check type of set_run_validators' arg
Implement attr.converters.default_if_none (#414)
Cache hash codes (#426)
Fade to Black (#392)
Disable hypothesis.HealthCheck.too_slow globally (#396)
Get rid of slangy anymore