Add LLCATS to base.py
Add LLCATS to base.py

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