Visions

FIX: Numpy backend
FIX: Compatibility fixes with new versions of pandas
ENH: Documentation updates
ENH: CI

FIX: bottleneck import removed (py3.9+ incompatible)

FEAT: Numpy and spark backends
DEPS: bottleneck dependency removed (py3.9+ incompatible)

FIX: CI issues
FIX: Unit tests with multiple pandas boolean types.
FIX: Documentation changes

* public methods on typesets are now static
* introduces a new declarative API
* documentation changes and fixes.

ENH: swifter apply for pandas backend
FIX: fix for issue 147
ENH: `__version__` attribute made available
ENH: improved typing and CI
ENH: contrib types/typesets for a low-threshold contribution of types