Non-flex children not supported for typescript

[ayc92]

Currently, if I do something like:

<Flexbox>
    <Flexbox flexGrow={1} />
    <Flexbox flex="0 0 45%" />
</Flexbox>

The children Flexbox elements will have display: flex even though I want them to be flex children rather than containers. This isn't a problem for regular javascript, because the propTypes aren't actually enforced, so you could just do <Flexbox display="block" /> for the child element (though even that seems really cumbersome). However, for typescript, the types are actually enforced by the compiler, and display is restricted to flex and inline-flex, so you wouldn't be able to hack around it as I showed above without a compiler error.

An unideal solution would be to not use Flexbox for children, but rather just plain elements, and then to define the flex properties for them elsewhere. However, I'd really rather just be able to use the same API as the container.