react-styleguidist: Do not work with Webpack 2.1.0-beta.23+

Webpack has introduced a config validation in beta23 which breaks our build:

WebpackOptionsValidationError: Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
 - configuration has an unknown property 'debug'. These properties are valid:
   object { amd?, bail?, cache?, context?, devServer?, devtool?, entry, externals?, loader?, module?, name?, dependencies?, node?, output?, plugins?, profile?, recordsInputPath?, recordsOutputPath?, recordsPath?, resolve?, resolveLoader?, stats?, target?, watch?, watchOptions? }
 - configuration.module.noParse should be one of these:
   [RegExp] | RegExp
   Don't parse files matching. It's matched against the full resolved request.
 - configuration.resolve has an unknown property 'moduleDirectories'. These properties are valid:
   object { modules?, descriptionFiles?, plugins?, mainFields?, aliasFields?, mainFiles?, extensions?, enforceExtension?, moduleExtensions?, enforceModuleExtension?, alias?, symlinks?, unsafeCache?, cachePredicate?, fileSystem?, resolver? }
 - configuration.resolve.extensions[0] should not be empty.
 - configuration.resolveLoader has an unknown property 'modulesDirectories'. These properties are valid:
   object { modules?, descriptionFiles?, plugins?, mainFields?, aliasFields?, mainFiles?, extensions?, enforceExtension?, moduleExtensions?, enforceModuleExtension?, alias?, symlinks?, unsafeCache?, cachePredicate?, fileSystem?, resolver? }

Not sure how we can make a config that works in Webpack 1 and 2.

https://github.com/webpack/webpack/releases/tag/v2.1.0-beta.23