updated a test in test_celllab
updated a test in test_celllab

landlab/landlab,laijingtao/landlab,landlab/landlab,csherwood-usgs/landlab,RondaStrauch/landlab,cmshobe/landlab,ManuSchmi88/landlab,amandersillinois/landlab,Carralex/landlab,Carralex/landlab,Carralex/landlab,RondaStrauch/landlab,cmshobe/landlab,ManuSchmi88/landlab,SiccarPoint/landlab,landlab/landlab,csherwood-usgs/landlab,amandersillinois/landlab,ManuSchmi88/landlab,laijingtao/landlab,RondaStrauch/landlab,cmshobe/landlab,SiccarPoint/landlab