Replace deprecated babel/polyfill with corejs/regenerator-runtim
Fix #914 (closed). @babel/polyfill
is deprecated and ships a deprecated version of corejs
too, see https://babeljs.io/docs/en/next/babel-polyfill.html.
I did not spot any related issues but there were some weird things (server restarting a lot due to changes on startup) so I put it as a WIP for now, if other have the time to test it too, please do.
Edited by Nicolas Frandeboeuf