Reactでprototypingする時にdocument.bodyにレンダリングすんな！って怒られた時の回避 ref: http://qiita.com/inuscript/items/552b8e332f95d0928b2b

file0.js

ReactDom.render(
　　<Main />, 
　　document.body
)

file1.txt

Warning: render(): Rendering components 
directly into document.body is discouraged,
since its children are often manipulated by third-party
scripts and browser extensions. 
This may lead to subtle reconciliation issues. 
Try rendering into a container element created for your app.

file2.js

ReactDom.render(
　　<Main />,
　　document.body.appendChild(document.createElement('div'))
)

index.js

ReactDom.render(
　　<Main />,
　　document.body.appendChild(document.createElement('div'))
)