Jest expect typings from https://github.com/DefinitelyTyped/DefinitelyTyped/tree/master/types/jest
This includes the entire jest namespace, but only declares expect, and not beforeEach, it etc.
Designed to be used alongside https://www.npmjs.com/package/expect
Why?
The complete @types/jest typings conflict with @types/mocha, as they both try to declare different global types such as beforeEach, it etc