Bump @babel/core from 7.8.4 to 7.8.6

Bumps [@babel/core](https://github.com/babel/babel) from 7.8.4 to 7.8.6.
- [Release notes](https://github.com/babel/babel/releases)
- [Changelog](https://github.com/babel/babel/blob/master/CHANGELOG.md)
- [Commits](babel/babel@v7.8.4...v7.8.6)

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