Don't check that creating sliver a second time fails.
Don't check that creating sliver a second time fails.

ahelsing/geni-tools,plantigrade/geni-tools,GENI-NSF/gram,tcmitchell/geni-tools,ahelsing/geni-tools,GENI-NSF/gram,plantigrade/geni-tools,tcmitchell/geni-tools,GENI-NSF/gram