chore(deps-dev): bump nyc from 15.0.1 to 15.1.0 (hexojs#205)

Bumps [nyc](https://github.com/istanbuljs/nyc) from 15.0.1 to 15.1.0.
- [Release notes](https://github.com/istanbuljs/nyc/releases)
- [Changelog](https://github.com/istanbuljs/nyc/blob/master/CHANGELOG.md)
- [Commits](istanbuljs/nyc@v15.0.1...v15.1.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>