Use RMG.log as log file name in generateReactions.
Use RMG.log as log file name in generateReactions.

The RMG.initializeLog() method currently assumes that the log file is
named RMG.log as part of how it backs up the log file. This change is
needed in order to be able to run generateReactions.

enochd/RMG-Py,nyee/RMG-Py,faribas/RMG-Py,nickvandewiele/RMG-Py,chatelak/RMG-Py,faribas/RMG-Py,enochd/RMG-Py,chatelak/RMG-Py,comocheng/RMG-Py,pierrelb/RMG-Py,nickvandewiele/RMG-Py,nyee/RMG-Py,KEHANG/RMG-Py,KEHANG/RMG-Py,comocheng/RMG-Py,pierrelb/RMG-Py