build: Update @types/node requirement to ~9.4.0 (#22)
build: Update @types/node requirement to ~9.4.0 (#22)

Updates the requirements on [@types/node](https://github.com/DefinitelyTyped/DefinitelyTyped) to permit the latest version.
- [Commits](https://github.com/DefinitelyTyped/DefinitelyTyped/commits)
stryker-mutator/stryker-badge,stryker-mutator/stryker-badge,stryker-mutator/stryker-badge,stryker-mutator/stryker-badge