[LIB_HUBZERO] add users model stub for interacting with new ORM
[LIB_HUBZERO] add users model stub for interacting with new ORM

zooley/hubzero-cms,zooley/hubzero-cms,anthonyfuentes/hubzero-cms,zweidner/hubzero-cms,anthonyfuentes/hubzero-cms,zooley/hubzero-cms,zweidner/hubzero-cms,zooley/hubzero-cms,anthonyfuentes/hubzero-cms,zweidner/hubzero-cms,zweidner/hubzero-cms,anthonyfuentes/hubzero-cms