Fix React 15.5.0 Warnings

[andrewzey]

Problem

• Get the following React console warnings:
  • warning.js:36 Warning: Accessing PropTypes via the main React package is deprecated. Use the prop-types package from npm instead.
  • warning.js:36 Warning: Legend: React.createClass is deprecated and will be removed in version 16. Use plain JavaScript classes instead. If you're not yet ready to migrate, create-react-class is available on npm as a drop-in replacement.

Cause

• Deprecations in React 15.5: https://facebook.github.io/react/blog/2017/04/07/react-v15.5.0.html#migrating-from-react.proptypes and https://facebook.github.io/react/blog/2017/04/07/react-v15.5.0.html#migrating-from-react.createclass

Changes

• Replace React.PropTypes with prop-types package
• Replace React.createClass with create-react-class package

[jseminck]

Any chance of having this merged any time soon?

[natec8]

It might be good to fix the failing tests, but if it gets merged in without fixing the tests, I will fix them.

[AlanFoster]

Thanks for the PR! A newer PR had tests passing, so I've gone ahead and merged that - and I will close this now 👍