adding total_seconds() calculation for python below 2.7 versions
adding total_seconds() calculation for python below 2.7 versions

warrenpnz/nagios-plugin-mongodb,Elbandi/nagios-plugin-mongodb,MingjunZhao/Mapscape-Nagios-Mongo,adrianlzt/nagios-plugin-mongodb,hdeheer/nagios-plugin-mongodb,mzupan/nagios-plugin-mongodb,alexp789/nagios-plugin-mongodb,a-yiorgos/nagios-plugin-mongodb,cookbooks/nd-nagios-plugin-mongodb