Bump num-rational from 0.3.0 to 0.3.1
Bump num-rational from 0.3.0 to 0.3.1

Bumps [num-rational](https://github.com/rust-num/num-rational) from 0.3.0 to 0.3.1.
- [Release notes](https://github.com/rust-num/num-rational/releases)
- [Changelog](https://github.com/rust-num/num-rational/blob/master/RELEASES.md)
- [Commits](https://github.com/rust-num/num-rational/compare/num-rational-0.3.0...num-rational-0.3.1)

Signed-off-by: dependabot-preview[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
shssoichiro/oxipng,shssoichiro/oxipng,shssoichiro/oxipng