Stylesheets are not minimized on production

[aganov]

Seems like stylesheet minimization is not enabled by default on production env. It was previously achieved by new webpack.LoaderOptionsPlugin({minimize: true}) in production.js but this was removed here a858f8e#diff-f83786ad580b744c4ee876b6fe21c138

I think we have 3 options to get back minimization:

• Get back webpack.LoaderOptionsPlugin({minimize: true}) to production.js
• Modify loaders/sass.js to something like use: [ { loader: 'css-loader', options: { minimize: env.NODE_ENV === 'production' } }, 'postcss-loader', 'sass-loader'] which seems ugly solution
• Add --optimize-minimize or -p options to webpack in webpacker:compile task

@gauravtiwari What do you think?

[dhh]

Fixed by #225.