Merge tag '1.6.0' into develop

Improvements
- Replacement of the complete image of the node by the alpine, which greatly reduces the size of the generated image;
- Update of the dependencies used in the application;
- Removal of last_sync from the route POST /v1/users/{child_id}/fitbit/auth.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "data-sync-agent",
-  "version": "1.5.9",
+  "version": "1.6.0",
   "description": "Service responsible for data synchronization of FitBit platform with OCARIoT platform.",
   "main": "dist/server.js",
   "scripts": {