Fix error in get_gene_names()
Fix error in get_gene_names()

- was previously appending on the gene lists in antibody_HGNC_dict as
  lists, not individually, to the antibody_gene_list

sorgerlab/indra,bgyori/indra,johnbachman/belpy,bgyori/indra,johnbachman/indra,bgyori/indra,sorgerlab/indra,pvtodorov/indra,sorgerlab/belpy,johnbachman/belpy,sorgerlab/belpy,sorgerlab/belpy,johnbachman/indra,pvtodorov/indra,sorgerlab/indra,johnbachman/belpy,johnbachman/indra,pvtodorov/indra,pvtodorov/indra