Updated ospurge.py file to delete more resources

Standard ospurge was not deleting below resources. I have added codes to delete below resources.

'NeutronFireWall',
'NeutronFireWallPolicy',
'NeutronFireWallRule',
'NeutronLbMembers',
'NeutronLbVip',
'NeutronLbHealthMonitor',
'NeutronLbPool',
'NeutronMeteringLabel',
'NeutronMeteringLabelRule'