Optimize React for production
Optimize React for production

- sets `process.env.NODE_ENV = 'production'` using `envify`
- elimates the (now dead) React development code with `uglifyify`
- based on guidance on how to use React with browserify: https://reactjs.org/docs/optimizing-performance.html#browserify
- fixes https://github.com/alanshaw/david-www/issues/390

alanshaw/david-www