Fix bug in measure/reaction.pyx (using 'rxn' where the variable is called 'reaction')
Fix bug in measure/reaction.pyx (using 'rxn' where the variable is called 'reaction')

Not sure how this used to compile, but cython balks at it now.
nyee/RMG-Py,comocheng/RMG-Py,chatelak/RMG-Py,nickvandewiele/RMG-Py,enochd/RMG-Py,pierrelb/RMG-Py,comocheng/RMG-Py,chatelak/RMG-Py,faribas/RMG-Py,enochd/RMG-Py,KEHANG/RMG-Py,nyee/RMG-Py,nickvandewiele/RMG-Py,pierrelb/RMG-Py,faribas/RMG-Py,KEHANG/RMG-Py