Added Timy Messenger to examples list (#157)

We recently open sourced the code of Timy Messenger, a large Flutter app that uses flutter_redux with Firebase.

It can be a good example for people looking for some real life examples, so maybe you would like to have it listed in your README.md, 
and also it would be an honour for me.

Thanks!

Author: miquelbeltran

README.md

@@ -30,6 +30,7 @@ Dart 2 requires more strict typing (yay!), and gives us the option to make getti
   * [Simple example](https://github.com/brianegan/flutter_redux/tree/master/example/counter) - a port of the standard "Counter Button" example from Flutter
   * [Github Search](https://github.com/brianegan/flutter_redux/tree/master/example/github_search) - an example of how to search as a user types, demonstrating both the Middleware and Epic approaches.
   * [Todo app](https://github.com/brianegan/flutter_architecture_samples/tree/master/redux) - a more complete example, with persistence, routing, and nested state.
+  * [Timy Messenger](https://github.com/janoodleFTW/timy-messenger) - large open source app that uses flutter_redux together with Firebase Firestore.
 
 ### Companion Libraries
   * [flipperkit_redux_middleware](https://pub.dartlang.org/packages/flipperkit_redux_middleware) - Redux Inspector (use [Flutter Debugger](https://github.com/blankapp/flutter-debugger)) for Flutter Redux apps