add gzip

[caranicas]

addressing #278

• added compression
• fixed site optimization
• fixed image optimization
• fixed text optimization

I don't see any image warnings, but I didn't see any previously either, so I can't confirm that this is optimizing the images on the site.

This was solved

Compressing https://react-webpack-node.herokuapp.com/ could save 8.1KiB (34% reduction).

These were not solved.

Compressing https://react-webpack-node.herokuapp.com/assets/app.js could save 196.6KiB (71% reduction).
Compressing https://react-webpack-node.herokuapp.com/assets/styles/main.css could save 1.9KiB (53% reduction).

@jrodl3r @psimyn @iljadaderko any ideas on how to get the text compression to work properly?

[psimyn]

I think app.use(express.compress()) before the express.static line should handle js/css, or maybe include compression earlier if it's meant to handle static as well

[caranicas]

@psimyn perfect.

[choonkending]

👍 🎉