Create a helper to adapt kabob-case and snake_case properties to camelCase

[rgbkrk]

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As mentioned by @gaearon in https://github.com/facebook/react/issues/11315#issuecomment-338469109, we should create an adapter that converts any kwargs to match what React expects exactly (as is also written in our spec).

[yuvipanda]

I started running into this problem in #64 too, with style attribute key case names.