Support npm v7

[tiagob]

npm v7 is out. It should support workspaces. npm install is only installing root packages though. It's ignoring workspaces

• https://github.com/npm/rfcs/blob/latest/implemented/0026-workspaces.md
• https://blog.npmjs.org/post/621733939456933888/npm-v7-series-why-keep-package-lockjson
• https://stackoverflow.com/questions/37485787/how-to-run-npm-install-without-changing-working-directory