add flavor creation tests
add flavor creation tests

1. verify that it can deal with string ram parameter
2. make sure it can detect invalid ram and vcpus

Change-Id: Ic439cdf6b8ff99c7b13efc849afb92b4b0865392

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