Bump minimist, mkdirp, mocha and handlebars in /advent-2019/shared

Bumps [minimist](https://github.com/minimistjs/minimist) to 1.2.7 and updates ancestor dependencies [minimist](https://github.com/minimistjs/minimist), [mkdirp](https://github.com/isaacs/node-mkdirp), [mocha](https://github.com/mochajs/mocha) and [handlebars](https://github.com/wycats/handlebars.js). These dependencies need to be updated together.


Updates `minimist` from 0.0.8 to 1.2.7
- [Release notes](https://github.com/minimistjs/minimist/releases)
- [Changelog](https://github.com/minimistjs/minimist/blob/main/CHANGELOG.md)
- [Commits](minimistjs/minimist@v0.0.8...v1.2.7)

Updates `mkdirp` from 0.5.1 to 0.5.4
- [Release notes](https://github.com/isaacs/node-mkdirp/releases)
- [Changelog](https://github.com/isaacs/node-mkdirp/blob/main/CHANGELOG.md)
- [Commits](isaacs/node-mkdirp@0.5.1...v0.5.4)

Updates `mocha` from 6.2.2 to 6.2.3
- [Release notes](https://github.com/mochajs/mocha/releases)
- [Changelog](https://github.com/mochajs/mocha/blob/master/CHANGELOG.md)
- [Commits](mochajs/mocha@v6.2.2...v6.2.3)

Updates `handlebars` from 4.5.3 to 4.7.7
- [Release notes](https://github.com/wycats/handlebars.js/releases)
- [Changelog](https://github.com/handlebars-lang/handlebars.js/blob/master/release-notes.md)
- [Commits](handlebars-lang/handlebars.js@v4.5.3...v4.7.7)

---
updated-dependencies:
- dependency-name: minimist
  dependency-type: indirect
- dependency-name: mkdirp
  dependency-type: indirect
- dependency-name: mocha
  dependency-type: direct:development
- dependency-name: handlebars
  dependency-type: indirect
...

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