Add tests for wait_for_server_status
Add tests for wait_for_server_status

Unit tests for wait_for_server_status, partially implements bp unit-tests.

Change-Id: I11a30291b99fd3f33b01ce3d96e084e7e708c998

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