fix(mongo-client): pass arguments to ctor when new keyword is used

Author: ORESoftware

lib/mongo_client.js

@@ -259,7 +259,7 @@ function validOptions(options) {
  * @return {MongoClient} a MongoClient instance
  */
 function MongoClient(url, options) {
-  if (!(this instanceof MongoClient)) return new MongoClient();
+  if (!(this instanceof MongoClient)) return new MongoClient(url, options);
 
   // Set up event emitter
   EventEmitter.call(this);