Typings for testHook are incorrect

[carlos-algms]

• react-testing-library version: 5.6.0

Relevant code or config:

node_modules\react-testing-library\typings\index.d.ts

Reproduction:

Problem description:

It is impossible to run tests using testHook with TypeScript due to incorrect typings definitions.

[alexkrolick]

Closed by #292

[carlos-algms]

Thank you so much for the fast solution.