Bump sinon from 2.4.1 to 4.1.3

Bumps [sinon](https://github.com/sinonjs/sinon) from 2.4.1 to 4.1.3.
- [Changelog](https://github.com/sinonjs/sinon/blob/master/History.md)
- [Commits](https://github.com/sinonjs/sinon/compare/v2.4.1...v4.1.3)