Darker icons

[DavidMcCourt]

The themes provided with the Web AppBuilder for ArcGIS all use white icons which look great on a dark background.

But not so good on a light background.

This project provides darker icons appropriate for a lighter background.

You can download the icons from https://github.com/softwhere/widget-icons/archive/master.zip

[RebeccaStrauch__GISP]

added to WAB resources list.  thanks.