Bump mongoose from 4.13.14 to 5.13.15 in /mean-news (#18)

Bumps [mongoose](https://github.com/Automattic/mongoose) from 4.13.14 to 5.13.15.
- [Release notes](https://github.com/Automattic/mongoose/releases)
- [Changelog](https://github.com/Automattic/mongoose/blob/master/CHANGELOG.md)
- [Commits](Automattic/mongoose@4.13.14...5.13.15)

---
updated-dependencies:
- dependency-name: mongoose
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]