pass fields from config to override default response attributes

[literat]

In project in our company we need to access attribute managedObjects on object user. In current implementation we cannot access this attribute because attributes in response are limited by default attributes which are set here https://github.com/jsumners/node-activedirectory/blob/jsumners/lib/activedirectory.js#L55.

So we need to override the defaultAttributes object and idea is to pass down default response attributes from construct of AD.

Please, let mi know, if there is a better way to solve this problem.

Thanks.