Removed deprecated node_index_at_active_cells.
Removed deprecated node_index_at_active_cells.

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