create-element-to-jsx-children: Convert .map calls into a JSXExpressi…

[elicwhite]

…onContainer

This didn't properly handle converting:

var React = require('React');

React.createElement(
  'div',
  null,
  foo.map(function() {})
);

to:

var React = require('React');

<div>{foo.map(function() {})}</div>;

Now it does! :)

[cpojer]

nice!