Drop OfficialClientTest and NetworkTest
Drop OfficialClientTest and NetworkTest

Migration of scenario tests to tempest clients is complete.
Drop the two base classes based on official clients, which
are now unused.

Change-Id: I21354541bace349fbc84bc5f5c0cf6e131ebbd01
Partially-implements: bp/tempest-client-scenarios

afaheem88/tempest,xbezdick/tempest,ebagdasa/tempest,JioCloud/tempest,izadorozhna/tempest,NexusIS/tempest,alinbalutoiu/tempest,LIS/lis-tempest,afaheem88/tempest_neutron,openstack/tempest,sebrandon1/tempest,flyingfish007/tempest,alinbalutoiu/tempest,LIS/lis-tempest,hayderimran7/tempest,pczerkas/tempest,NexusIS/tempest,pandeyop/tempest,cisco-openstack/tempest,jaspreetw/tempest,pandeyop/tempest,yamt/tempest,izadorozhna/tempest,varunarya10/tempest,Juniper/tempest,masayukig/tempest,queria/my-tempest,jamielennox/tempest,bigswitch/tempest,masayukig/tempest,manasi24/tempest,Juraci/tempest,Vaidyanath/tempest,redhat-cip/tempest,Vaidyanath/tempest,vedujoshi/tempest,flyingfish007/tempest,eggmaster/tempest,nunogt/tempest,varunarya10/tempest,yamt/tempest,dkalashnik/tempest,zsoltdudas/lis-tempest,Juniper/tempest,rakeshmi/tempest,openstack/tempest,tonyli71/tempest,Juraci/tempest,manasi24/tempest,Lilywei123/tempest,manasi24/jiocloud-tempest-qatempest,pczerkas/tempest,afaheem88/tempest,Lilywei123/tempest,akash1808/tempest,zsoltdudas/lis-tempest,dkalashnik/tempest,jaspreetw/tempest,rakeshmi/tempest,manasi24/jiocloud-tempest-qatempest,cisco-openstack/tempest,xbezdick/tempest,Tesora/tesora-tempest,queria/my-tempest,neerja28/Tempest,hayderimran7/tempest,hpcloud-mon/tempest,tudorvio/tempest,CiscoSystems/tempest,akash1808/tempest,FujitsuEnablingSoftwareTechnologyGmbH/tempest,hpcloud-mon/tempest,roopali8/tempest,sebrandon1/tempest,jamielennox/tempest,CiscoSystems/tempest,tudorvio/tempest,eggmaster/tempest,rzarzynski/tempest,FujitsuEnablingSoftwareTechnologyGmbH/tempest,neerja28/Tempest,Tesora/tesora-tempest,vedujoshi/tempest,bigswitch/tempest,rzarzynski/tempest,ebagdasa/tempest,tonyli71/tempest,danielmellado/tempest,afaheem88/tempest_neutron,danielmellado/tempest,JioCloud/tempest,nunogt/tempest,roopali8/tempest,redhat-cip/tempest