add a gradient option to path_options (#1433)
add a gradient option to path_options (#1433)

* add a gradient option to path_options to allow removing the gradient added by leaflet-dvf

* typo fix

* fix docstring

Co-authored-by: Frank <ea323900f6656823ec7b7ef06af01c318e1b2f1a@users.noreply.github.com>
python-visualization/folium,python-visualization/folium