chore: update backendless.js to v3.1.5

Author: vengrov

package.json

@@ -33,7 +33,7 @@
     "backendless"
   ],
   "dependencies": {
-    "backendless": "^3.1.2",
+    "backendless": "^3.1.5",
     "commander": "^2.9.0",
     "glob": "^6.0.4",
     "jszip": "^2.5.0",