Bump structopt-derive from 0.2.18 to 0.3.0 (#103)
Bump structopt-derive from 0.2.18 to 0.3.0 (#103)

Bumps [structopt-derive](https://github.com/TeXitoi/structopt) from 0.2.18 to 0.3.0.
- [Release notes](https://github.com/TeXitoi/structopt/releases)
- [Changelog](https://github.com/TeXitoi/structopt/blob/master/CHANGELOG.md)
- [Commits](https://github.com/TeXitoi/structopt/compare/v0.2.18...v0.3.0)

Signed-off-by: dependabot-preview[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
alex/ct-tools,alex/ct-tools