Show system notifications for errors

Created by: goshacmd

Uses webpack-notifier under the hood. No setup necessary. Supports Notification Center on OS X, Toaster on Windows 8 and later. Falls back to Growl if present.

(https://github.com/mikaelbr/node-notifier/blob/master/DECISION_FLOW.md)

Ref #89 (closed).

Notifications look like this:

for this error:

Error in ./src/App.js
Syntax error: /Users/goshakkk/Projects/oss/create-react-app/demo/src/App.js: Unexpected token (11:38)
   9 |         <div className="App-header">
  10 |           <img src={logo} className="App-logo" alt="logo" />
> 11 |           <h2>Welcome to React z</h2><<div
     |                                       ^
  12 |         </div>
  13 |         <p className="App-intro">
  14 |           To get started, edit <code>src/App.js</code> and save to reload.
 @ ./src/index.js 11:11-27

• Possible to supply a custom image to webpack-notifier, could be React logo. Considerations: eject will have to copy the logo as well. Might be okay though.

• Custom title is supported by webpack-notifier. "React" might be a bit too broad, "React Scripts" or "Create React App" or "React CLI" might be better.

• Custom error formatter is not supported, plus terminal coloring artifacts are present ([4m). Not currently possible to supply a custom formatter to webpack-notifier. Ideally the message should have been

  Error: ./App.js Unexpected token (11:38)

  Full path & parts of stack trace seem irrelevant for the notification. Error message is much more informative.