Service must be fault-tolerant and handle exceptions

[Marcello DeSales]

🥅 Error handling

• Network connectivity.
• File-system is not ready.

🥇 Implemented all the EC6 code style

• Moved from prototype to EC6: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes
• Binding to the fs.watch method https://javascript.info/bind