Arrow function does not have prototype

[RettentoRectangle]

Hello,

First of all I'd like to thanks for this lib but I think I found a bug in it.

Example code:
const B = (props) => (<A foo="predefined" { ...props } />)

In dom composeToFunction function there is a row:
var bridge = JSXTag.prototype.render ? new JSXTag(props).render : JSXTag;

You are trying to check JSXTag.prototype.render function but when you pass arrow function there is no prototype.

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/Arrow_functions#Use_of_prototype_property

It would be fantastic if you could fix this. :)
Use this:
var bridge = JSXTag.prototype && JSXTag.prototype.render ? new JSXTag(props).render : JSXTag;

Cheers, keep up the good work!