remove equivalences between GeneReviews and OMIM genes
remove equivalences between GeneReviews and OMIM genes

* some OMIM genes were being created as equivalent classes to GeneReviews 'diseases'.  these were now completely removed by calling OMIM api to fetch the type of omim entry type, and filtering out those things that are genes/features.
* closes #202

monarch-initiative/dipper,TomConlin/dipper,monarch-initiative/dipper,monarch-initiative/dipper,TomConlin/dipper