The `formatter` option is incompatible with with `thread-loader`.
The `formatter` option previously accepted a function which was lost during JSON serialization.

* Update jest version

* Update babel-jest version

* Use testURL: http://localhost in jest configs.

* Update to jest version 23.5

This version of jest includes a fix for https://github.com/jsdom/jsdom/issues/2304

* "testURL": "http://localhost" is default with jest v23.5

This fixes the functionality of this dependency for Node 10 and above.

Refs: https://github.com/webpack/webpack-dev-server/pull/1451
Refs: https://github.com/nodejs/node/issues/21665

* Use file name whitelist to prevent RCE

Use a whitelist to validate user-provided file names. This doesn't cover
the entire range of valid filenames but should cover almost all of them
in practice. Allows letters, numbers, periods, dashes, and underscores.
Opting to use a whitelist instead of a blacklist because getting this
wrong leaves us vulnerable to a RCE attack.

* Allow alphabet characters from all languages

Updated the whitelist to /^[\p{L}0-9/.\-_]+$/u, which matches
alphanumeric characters, periods, dashes, and underscores. Unicode
property support is stage 4 so I've inlined the transpiled version.

* Only use file name whitelist on Windows

* Log error message if file name does not pass whitelist

* support scoped packages for cra --scripts-version option

* enable safe option to cssnano processor

Fixes #4682

* Add Node 10 to Travis config. Remove Node 6.

* Add Node 10 to Appveyor config. Remove Node 6.

* Remove node 9 from travis config.

* Increase mocha timeout.

* Update minimum Node version to 8.

* Update yarn to latest on Travis.

* Update old-node test to use Node 4.

* Increase mocha timeout in kitchensink-eject tests.

* Update yarn to latest on Appveyor.

* support scoped packages for cra --scripts-version option

* seperate out kitchensink test

* add eject to node 6 testing

* travis node 6 eject

* fix CI warnings

* Suggest `reactstrap` instead of `react-bootstrap`

* Update README.md

* node10

* token

* rerun tests

Allow bundles to be analyzed with Webpack-specific tools

Update file tree view

enable manifest plugin on dev

To analyze Webpack bundles, a "stats" JSON is required.

This PR allows that file to be created and saved to the `build`
directory, so that users can use it with Webpack-specific insight
tools like `webpack-bundle-analyzer` without ejecting their
application.

Updated the README to include details for how to do this.