Transition from setup.py to pyproject.toml

[hackdna]

"To avoid executing arbitrary scripts and boilerplate code, we are transitioning into a full-fledged setup.cfg to declare your package information instead of running setup()"
https://setuptools.pypa.io/en/latest/userguide/quickstart.html#transitioning-from-setup-py-to-setup-cfg

Test branch: https://github.com/onnela-lab/forest/tree/packaging-update

Required for #244

[hackdna]

It looks like pyproject.toml is the new standard for declaring project metadata: https://packaging.python.org/en/latest/specifications/declaring-project-metadata/#declaring-project-metadata

discussion:
https://www.reddit.com/r/learnpython/comments/yqq551/pyprojecttoml_setupcfg_setuppy_whats_the/
https://lincolnloop.com/insights/using-pyprojecttoml-in-your-django-project/

[hackdna]

Warning when running pip:

DEPRECATION: Legacy editable install of forest==0.1.1 (setup.py develop) is deprecated. pip 25.0 will enforce this behaviour change. A possible replacement is to add a pyproject.toml or enable --use-pep517, and use setuptools >= 64. If the resulting installation is not behaving as expected, try using --config-settings editable_mode=compat. Please consult the setuptools documentation for more information. Discussion can be found at pypa/pip#11457

[hackdna]

Addressed in ae6f171