postcss-loader v4.0.0 released

[grcenneat]

Due to the latest version of postcss-loader(v4.0.0) released on 9/7, an error ModuleBuildError occurs.

👇 Error message:

Module build failed (from ./node_modules/mini-css-extract-plugin/dist/loader.js):
ModuleBuildError: Module build failed (from ./node_modules/postcss-loader/dist/cjs.js):
ValidationError: Invalid options object. PostCSS Loader has been initialized using an options object that does not match the API schema.

Check major changes in release note,

• PostCSS (plugins/syntax/parser/stringifier) options was moved to the postcssOptions option, please look at docs

There are two ways to fix this.

1. Change PostCss to postcssOptions
2. Fix postcss-loader version to 3.0.0 in package.json

The first method seems better, so let me make a pull request using the first method.

[iliakan]

Thanks, we'll be staying on 3 for some time.