Webpack dev vs production styles

[morganecf]

Currently we have two different ways of serving styles:

In production (webpack.prod.js), we minify the CSS. For dev builds, we use style-loader.

This means that if you add a rule to an scss file, it'll show up via style-loader, but if you delete a rule it'll still show up via the minified styles.css if it was in the latest production build.

For now I'm just commenting out styles.css in index.html, but we should figure out how to prevent these from colliding