CSS is not minified in prod build with master

Created by: trygveaa

Can you reproduce the problem with latest npm?

Yes

Description

When I'm building to production with the master version of create-react-app, the css is not minified. With the latest released version (v0.9.5) however, it is being minified.

Expected behavior

The css file under build/static/css/ should be minified.

Actual behavior

It is not minified.

Environment

Run these commands in the project folder and fill in their results:

npm ls react-scripts (if you haven’t ejected): Running from master, see below.
node -v: v7.7.3
npm -v: 4.4.4

Then, specify:

Operating system: Arch Linux
Browser and version: Irrelevant

Reproducible Demo

I can reproduce this by running these commands:

git clone git@github.com:facebookincubator/create-react-app.git .
npm i
npm run create-react-app test-css-minify
cd test-css-minify
npm run build

And looking at the css file that is built under build/static/css/.