Update num requirement from 0.1 to 0.3
Update num requirement from 0.1 to 0.3

Updates the requirements on [num](https://github.com/rust-num/num) to permit the latest version.
- [Release notes](https://github.com/rust-num/num/releases)
- [Changelog](https://github.com/rust-num/num/blob/master/RELEASES.md)
- [Commits](https://github.com/rust-num/num/compare/num-0.1.28...num-0.3.0)

Signed-off-by: dependabot-preview[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
aepsil0n/acacia