Use 5 neutron clients from tempest-lib

The files below have been migrated to tempest-lib

 * metering_label_rules_client.py: Ic840c3697f727612dfe754948e9a5890e7f2505d
 * metering_labels_client.py     : Ic840c3697f727612dfe754948e9a5890e7f2505d
 * networks_client.py            : Ic840c3697f727612dfe754948e9a5890e7f2505d
 * ports_client.py               : Ic840c3697f727612dfe754948e9a5890e7f2505d
 * subnets_client.py             : Ic840c3697f727612dfe754948e9a5890e7f2505d

Now Tempest-lib provides those as stable interfaces. So Tempest should
start using those from lib and remove its own copy.

Change-Id: I83daa612fb36b83da507484b9752f8b1ffacd2a7
8 files changed