build(deps): bump debug, express and mongoose

Bumps [debug](https://github.com/debug-js/debug) to 4.3.5 and updates ancestor dependencies [debug](https://github.com/debug-js/debug), [express](https://github.com/expressjs/express) and [mongoose](https://github.com/Automattic/mongoose). These dependencies need to be updated together.


Updates `debug` from 4.1.1 to 4.3.5
- [Release notes](https://github.com/debug-js/debug/releases)
- [Commits](debug-js/debug@4.1.1...4.3.5)

Updates `debug` from 3.2.6 to 4.3.5
- [Release notes](https://github.com/debug-js/debug/releases)
- [Commits](debug-js/debug@4.1.1...4.3.5)

Updates `express` from 4.12.4 to 4.19.2
- [Release notes](https://github.com/expressjs/express/releases)
- [Changelog](https://github.com/expressjs/express/blob/master/History.md)
- [Commits](expressjs/express@4.12.4...4.19.2)

Updates `mongoose` from 4.2.4 to 4.13.21
- [Release notes](https://github.com/Automattic/mongoose/releases)
- [Changelog](https://github.com/Automattic/mongoose/blob/master/CHANGELOG.md)
- [Commits](Automattic/mongoose@4.2.4...4.13.21)

---
updated-dependencies:
- dependency-name: debug
  dependency-type: indirect
- dependency-name: debug
  dependency-type: indirect
- dependency-name: express
  dependency-type: direct:production
- dependency-name: mongoose
  dependency-type: direct:production
...

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

Author: dependabot[bot]