[MIGRATIONS] account for scenario where table may need to be removed
[MIGRATIONS] account for scenario where table may need to be removed

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