Update mongodb to the latest version 🚀 (parse-community#5162)

* fix(package): update mongodb to version 3.1.9

* chore(package): update lockfile package-lock.json

Author: greenkeeper[bot]

package-lock.json

@@ -33,7 +33,7 @@
     "lodash": "4.17.11",
     "lru-cache": "4.1.3",
     "mime": "2.3.1",
-    "mongodb": "3.1.8",
+    "mongodb": "3.1.9",
     "parse": "2.1.0",
     "pg-promise": "8.5.1",
     "redis": "2.8.0",