Devices can now subscribe to specific topics.

- Device can now become (in)active
- Error alert makes sound
- Alerts now execute function on click

backend/app.ts

@@ -92,7 +92,7 @@ async function run() {
     /**
      * Database connection
      */
-    mongoose.set('debug', true);
+    //mongoose.set('debug', true);
     const connection = await mongoose.connect(MONGO_URI, { useNewUrlParser: true, useUnifiedTopology: true }).catch((err) => {
         logger.crit("Database connection could not be made: ", err);
         exit(1);