[Docs] Update list of enzyme-adapter-react-16 peer dependencies
[Docs] Update list of enzyme-adapter-react-16 peer dependencies

Since as of #1252, `enzyme-adapter-react-16` has `react-test-renderer`
as a `dependency` rather than a `peerDependency`, so users of enzyme
no longer need to manually install it.

airbnb/enzyme,airbnb/enzyme