fixing failing testToAdjacencyList()
fixing failing testToAdjacencyList()

The number of lone electron pairs is not defined for groups, therefore
should not be printed for groups 
comocheng/RMG-Py,nyee/RMG-Py,nickvandewiele/RMG-Py,pierrelb/RMG-Py,nickvandewiele/RMG-Py,KEHANG/RMG-Py,faribas/RMG-Py,chatelak/RMG-Py,comocheng/RMG-Py,enochd/RMG-Py,nyee/RMG-Py,faribas/RMG-Py,pierrelb/RMG-Py,chatelak/RMG-Py,enochd/RMG-Py,KEHANG/RMG-Py