Make sure uuid_list for group edges is unique
Make sure uuid_list for group edges is unique

The process of building up the list could potentially introduce a duplicate
uuid. Make sure the list is a set of uuids.

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