message: Fix bug where yarn run dev would break if user only saved a scss file.
diff: @@ -87,7 +87,7 @@ let config = {
  new HtmlWebpackPlugin({
  filename: './index.html',
  template: './public/index.html',
  - production: process.env.NODE_ENV === 'production',
  + production: process.env && process.env.NODE_ENV === 'production',
  }),
  new webpack.ContextReplacementPlugin(/moment[/\\]locale$/, /en/),
  ],
  @@ -96,7 +96,7 @@ let config = {
  };
  /* Production settings */
  -if (process.env.NODE_ENV === 'production') {
  +if (process.env && process.env.NODE_ENV === 'production') {
  config.output.filename = `[name]-bundle.${gitHash()}.min.js`;
  config.output.chunkFilename = `[name]-[chunkhash].${gitHash()}.min.js`;
  extractSass.filename = `app-bundle.${gitHash()}.min.css`;
  