Update dependency bluebird to v3.7.0

Author: renovate-bot

1.6/package.json

@@ -8,7 +8,7 @@
     "test": "echo \"Error: no test specified\" && exit 1"
   },
   "dependencies": {
-    "bluebird": "3.5.1",
+    "bluebird": "3.7.0",
     "qs": "6.5.1",
     "request-promise": "4.2.2",
     "xml2js": "0.4.19"