Does not handle additionalProperties

[jukeblimp32]

I've been using your library to validate requests, and it's been working great except for when it comes to additionalProperties.

The two methods I've tried of getting this to work are:

1. Specify in the the request object that:
   required:
   -additionalProperties
2. Specify in the referenced object within additionalProperties that each field is required.

With the first method, I always get failed validation because it is looking for an "additionalProperties" key. On the second method, if I don't include one of the fields that's required in the additionalProperties, I do not get a validation error.