upgrade to react 16

[bnchdrff]

https://reactjs.org/blog/2017/09/26/react-v16.0.html

https://github.com/facebook/react/releases/tag/v16.0.0

• [x] remove dependency on react-foundation-components from everything but voting widget #2253
• [x] fix our proptype definitions & switch to the standalone lib #2777
• [x] rewrite voting widget so that it does not depend on react-foundation-components, and remove react-foundation-components #2804
• [ ] ?

[gl2748]

related: https://github.com/steemit/condenser/issues/2253

[gl2748]

A pre-cursor to this work would be fixing our prop-types warnings:

[bnchdrff]

just started a checklist in the issue description

[gl2748]

To finish this:

• [ ] Remove custom shouldComponentUpdate like this - 26c40c65330a02740a0579953201c5c7247ad47f
• [ ] Remove react-perf like this - 13e39061fb0daa405ef0cb8539fb8d83a906c8c0
• [ ] Jest/Enzyme update to react 16 like this - https://github.com/steemit/condenser/commit/de9c8f2efcacb6e12ef670c957810089ded2ac4f
• [ ] Remove React-perf stuff like this - https://github.com/steemit/condenser/commit/13e39061fb0daa405ef0cb8539fb8d83a906c8c0
• [ ] Remove React-qr like this - https://github.com/steemit/condenser/commit/26c40c65330a02740a0579953201c5c7247ad47f#diff-908cd8c46c84f5f250f8f6df6338e860
• [ ] Remove React-Notification like this - https://github.com/steemit/condenser/commit/26c40c65330a02740a0579953201c5c7247ad47f#diff-67815eb68d09b43d508816d28b7d1764L6

[roadscape]

At a glance, it looks like https://github.com/steemit/condenser/pull/2909/files covers all the points in the last comment.