Add a server console-log test with unlimited length
Add a server console-log test with unlimited length

Now server console-log API is important for debugging gate problems
and the API is called with unlimited length for debugging. However,
there is not the API test with unlimited length.
This patch adds the test.

Change-Id: I5a35f086deddfcd54e995cb1156699592d1daea6

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