chore(package): update bluebird to version 3.4.6

https://greenkeeper.io/

Author: greenkeeperio-bot

package.json

@@ -14,14 +14,13 @@
   ],
   "dependencies": {
     "es6-promise": "3.2.1",
-    "mongodb-core": "2.0.11",
     "mongodb-core": "christkv/mongodb-core#2.0",
     "readable-stream": "2.1.5"
   },
   "devDependencies": {
     "JSONStream": "^1.0.7",
     "betterbenchmarks": "^0.1.0",
-    "bluebird": "3.4.3",
+    "bluebird": "3.4.6",
     "bson": "^0.5.1",
     "cli-table": "^0.3.1",
     "co": "4.6.0",