flexGrow/Shink/Basis not supported
Currently the documentation says these are supported.

I believe this would be fixed by upgrading to Yoga (#52).

I believe we want to do something like [this](https://github.com/orta/jest-snapshots-svg/blob/master/src/component-to-node.ts).

I'm happy to look at this. Would you be happy for something like the approach like above?