Update babel7 to the latest version 🚀 (#6520)

* chore(package): update @babel/core to version 7.9.0

* chore(package): update @babel/plugin-proposal-object-rest-spread to version 7.9.0

* chore(package): update @babel/plugin-transform-flow-strip-types to version 7.9.0

* chore(package): update @babel/preset-env to version 7.9.0

* chore(package): update lockfile package-lock.json

Co-authored-by: greenkeeper[bot] <23040076+greenkeeper[bot]@users.noreply.github.com>

Author: greenkeeper[bot]