change BNG path env var to match what BNG itself uses
change BNG path env var to match what BNG itself uses

jmuhlich/pysb,d-fan/pysb,spgarbet/pysb,johnbachman/pysb,spgarbet/pysb,neurord/pysb,alubbock/pysb,spgarbet/pysb,pysb/pysb,d-fan/pysb,neurord/pysb,neurord/pysb,LoLab-VU/pysb,d-fan/pysb,LoLab-VU/pysb,johnbachman/pysb