added reverse coefficent test for Troe format
added reverse coefficent test for Troe format

pierrelb/RMG-Py,pierrelb/RMG-Py,chatelak/RMG-Py,nyee/RMG-Py,nickvandewiele/RMG-Py,chatelak/RMG-Py,nyee/RMG-Py,nickvandewiele/RMG-Py