Autoprefixer now displays warning: `Replace Autoprefixer browsers option to Browserslist config`

A recent update to Autoprefixer postcss plugin must have introduced a warning to move to a newer configuration. The full warning I get is:
```sh
Replace Autoprefixer browsers option to Browserslist config.
Use browserslist key in package.json or .browserslistrc file.

Using browsers option cause some error. Browserslist config
can be used for Babel, Autoprefixer, postcss-normalize and other tools.

If you really need to use option, rename it to overrideBrowserslist.

Learn more at:
https://github.com/browserslist/browserslist#readme
https://twitter.com/browserslist
```