Babel + updates - Githubissues

npm: Switch to latest of acorn, chai, husky, lint-staged, mocha
npm: Switch engines to require Node 10+
npm: Replace @rollup/plugin-buble with @rollup/plugin-babel + @babel/preset-env
Build: Ensure using babel for ESM builds in case needed for any non-ESM features

d3x0r / JSON6