"autofocus" prop in TodoHeader's input is an "unknown prop"

[rouzazari]

First of all, thanks for the great tutorial and accompanying github repo.

Description

I noticed this error when walking through your tutorial. While "autofocus" is an HTML attribute for , you will get an error message in react 15.3.1 (and possibly other versions).

Warning: Unknown prop autofocus on tag. Remove this prop from the element. For details, see https://fb.me/react-unknown-prop
in input (created by TodoHeader)
in header (created by TodoHeader)
in TodoHeader (created by TodoApp)
in section (created by TodoApp)
in div (created by TodoApp)
in TodoApp

Fix

The fix is simple: it should be autoFocus (camelCase wins in JSX). I can submit a simple PR to fix the issue, or I'll leave it to you.

[rouzazari]

With react 0.14.7 (as specified in your packages.json) the error message does not appear; however, the autofocus feature does not work unless you use camelCase, i.e. it should read autoFocus.