Bump @babel/core from 7.7.7 to 7.8.4 (#481)

* Bump @babel/core from 7.7.7 to 7.8.4

Bumps [@babel/core](https://github.com/babel/babel) from 7.7.7 to 7.8.4.
- [Release notes](https://github.com/babel/babel/releases)
- [Changelog](https://github.com/babel/babel/blob/master/CHANGELOG.md)
- [Commits](babel/babel@v7.7.7...v7.8.4)

Signed-off-by: dependabot-preview[bot] <[email protected]>

* Update other `@babel/*` packages

Co-authored-by: Rob Brackett <[email protected]>

Author: dependabot-preview[bot]