Packages upgrade (bootstrap 4)

[noud]

trafficstars

hi,

i did update most packages. result after yarn start still works as-far-as-i-see exact like before.

bootstrap went from 3 to 4 as well did i use package.json for the existing css files.

i am unable to upgrade the jsplumb package.

ow and another, i lost that red banner about github.

Noud