Bump handlebars from 4.0.5 to 4.0.12

Bumps [handlebars](https://github.com/wycats/handlebars.js) from 4.0.5 to 4.0.12.
- [Release notes](https://github.com/wycats/handlebars.js/releases)
- [Changelog](https://github.com/wycats/handlebars.js/blob/master/release-notes.md)
- [Commits](https://github.com/wycats/handlebars.js/compare/v4.0.5...v4.0.12

)

Signed-off-by: dependabot[bot] <support@dependabot.com>
Signed-off-by: Christoph Wurst <christoph@winzerhof-wurst.at>
Signed-off-by: Roeland Jago Douma <roeland@famdouma.nl>