Fix numeric keys for dict inputs in tojavascript#2100

hansthen merged 2 commits intomainpython-visualization/folium:mainfrom

2098-gradient-parameter-in-heatmap-in-newest-version-cant-work-float-object-has-no-attribute-splitpython-visualization/folium:2098-gradient-parameter-in-heatmap-in-newest-version-cant-work-float-object-has-no-attribute-splitCopy head branch name to clipboard