Remove RestClientException inheritance
Remove RestClientException inheritance

The rest_client module doesn't raise AuthenticationFailur, so this
patch removes the inheritance.
In addition, this patch changes the order of exceptions for knowing
what exceptions the rest_client module raises.

Change-Id: Ia60ba728bdc650542602382eacbd35149717ecf7

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