MAINT: fix string key
MAINT: fix string key

mnicholl/MOSFiT,mnicholl/MOSFiT,guillochon/MOSFiT,guillochon/FriendlyFit,bmockler/MOSFiT,villrv/MOSFiT,bmockler/MOSFiT,guillochon/MOSFiT,villrv/MOSFiT,guillochon/MOSFiT,mnicholl/MOSFiT