Improved FindCyclusCore to use environment variables.
Improved FindCyclusCore to use environment variables.

sskutnik/TutorialStorage,Baaaaam/cyBaM,katyhuff/StreamBlender,scopatz/Bright-lite,jlittell/cycamore,sskutnik/CommodConverter,gonuke/TutorialStorage,katyhuff/CommodConverter,FlanFlanagan/fuelfab,gonuke/cycamore,rwcarlsen/cycamore,mbmcgarry/TutorialStorage,katyhuff/CommodConverter,cyclus/cycstub,jlittell/cycamore,jlittell/Storage,cyclus/cycstub,katyhuff/SeparationMatrix,katyhuff/SeparationMatrix,gonuke/TutorialStorage,rwcarlsen/cycamore,sskutnik/TutorialStorage,sskutnik/CommodConverter,katyhuff/MktDrivenInst,Baaaaam/cyCLASS,harrisgreenberg/tutorial,jdangerx/TutorialStorage,harrisgreenberg/tutorial,katyhuff/StreamBlender,Baaaaam/cycamore,cyclus/cycaless,rwcarlsen/cycamore,katyhuff/MktDrivenInst,gidden/cycstub,gonuke/cycamore,jdangerx/TutorialStorage,Baaaaam/cycamore,gonuke/cycamore,scopatz/Bright-lite,Baaaaam/cyBaM,mbmcgarry/TutorialStorage,jlittell/cycamore,gidden/cycstub,jlittell/Storage,gonuke/cycamore,Baaaaam/cyBaM,cyclus/cycaless,Baaaaam/cyCLASS,FlanFlanagan/fuelfab,Baaaaam/cyBaM,rwcarlsen/cycamore,Baaaaam/cycamore,jlittell/cycamore