Extractor: MBD files are not handled by Windows machines

[nicseltzer]

Citing: NatLabRockies/ditto#188

The get_mdb_data() function will not execute on a Windows machine. It requires the ability to execute an external command which is not compatible with Windows at this time.

https://github.com/OpenSTL/StlOpenDataEtl/blob/master/etl/extractor.py#L58