recommend filterwarnings=["error"] for pytest (#160)
recommend filterwarnings=["error"] for pytest (#160)

* recommend filterwarnings=["error"] for pytest

* Update pages/developers/style.md

Co-authored-by: Henry Schreiner <eb9c702a5237976b7b997483496bc5260300736e@gmail.com>
scikit-hep/scikit-hep.github.io,scikit-hep/scikit-hep.github.io,scikit-hep/scikit-hep.github.io,scikit-hep/scikit-hep.github.io