Updae d3 node module to 5.0
d3 node module is one major version behind at 4.13.0. It'd be a good idea to update to d3 5.x. We noticed 4.13.0 no longer builds with rollup 1.0 and it means maintaining the code ourselves.
These are the full changes https://github.com/d3/d3/blob/master/CHANGES.md#changes-in-d3-50
D3 now uses Promises instead of asynchronous callbacks to load data.