Fixed broken unit tests for structured_grid.
Fixed broken unit tests for structured_grid.

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