Issue with ReactDOM.hydrate and RNW 0.2.2

[leggomuhgreggo]

I think there's a minor bug with hydrate and RWN 0.2.2

When developing (using CRA) the following error prints to the console:
Warning: Expected server HTML to contain a matching <div> in <div>.

Whipped up a reduced demo case here.

Looking into it I found a relevant issue created on the React repo, and a PR from the react-static repo that might serve as the basis for a solution.

Might be as simple as conditioning between hydrate and render based on whether HMR is being used in renderApplication.js

Thanks!

[clayrisser]

#918