Merge pull request #769 from kentcdodds/patch-2

add reference to react-testing-library

content/docs/addons-test-utils.md

@@ -20,6 +20,8 @@ var ReactTestUtils = require('react-dom/test-utils'); // ES5 with npm
 > Note:
 >
 > Airbnb has released a testing utility called Enzyme, which makes it easy to assert, manipulate, and traverse your React Components' output. If you're deciding on a unit testing utility to use together with Jest, or any other test runner, it's worth checking out: [http://airbnb.io/enzyme/](http://airbnb.io/enzyme/)
+>
+> Alternatively, there is another testing utility called react-testing-library designed to enable and encourage writing tests that use your components as the end users use them. It also works with any test runner: [https://git.io/react-testing-library](https://git.io/react-testing-library)
 
  - [`Simulate`](#simulate)
  - [`renderIntoDocument()`](#renderintodocument)