enable tempest by default
enable tempest by default

turn on tempest by default, as that will provide the end users
with a testing environment to use with openstack out of the box.

Change-Id: I74160a25cfbc6325eea30c81df36e6acbb938bfd

JioCloud/devstack,ewindisch/raspi-devstack,samgoon/devstack,vsham20/devstack,wenhuizhang/devstack,ozamiatin/devstack,virtualopensystems/devstack,group-policy/devstack,andrewrothstein/devstack,nuxeh/devstack,HPCHub/devstack,promptworks/devstack,bq-xiao/devstack,pczerkas/devstack,HPCHub/devstack,Millnert/contrail-devstack,eharney/devstack,upadhyay-prashant/devstack,BSJAIN92/OpenStack,bswartz/devstack,Yuriy-Leonov/devstack,avvocatodemarchis/devstack,flavio-fernandes/devstack,costingalan/devstack,dtroyer/devstack,shootstar/devstacktest,herrsechs/devstack,liuquansheng47/devstack,group-policy/devstack,nawawi/openstack,openstack-dev/devstack,deepakselvaraj/devstack,mc2014/devstack,rushiagr/devstack,openstack-dev/devstack,pombredanne/devstack,atulpatil301/devstack,parul24/devstack,cloudbuilders/devstack,j4/devstack,Mahito/devstack,eharney/devstack,cloudbuilders/devstack,herrsechs/devstack,mmasaki/devstack,BSJAIN92/OpenStack,bswartz/devstack,LoHChina/devstack,wenhuizhang/devstack,CloudServer/devstack,Mahito/devstack,rushiagr/devstack,sstrato/devstack,Juniper/devstack,dtroyer/devstack,neerja28/Devstack_GlusterFS,richliu/devstack,TwinkleChawla/devstack,olivierlemasle/devstack,pacinete/devstack,affo/devstack,affo/devstack,pacinete/devstack,varunarya10/devstack,promptworks/devstack,neerja28/Devstack_GlusterFS,vishnugonela/devstack,pombredanne/devstack,bljgaurav/openstack-test,armando-migliaccio/devstack,williamthegrey/devstack,bigswitch/devstack,NaokiMiyata/devstack,bq-xiao/devstack,bljgaurav/openstack-test,mmasaki/devstack,mssumanth/devstack,dirkmueller/devstack,sequenceiq/devstack,jamielennox/devstack,yamt/devstack,innodee/openstackk,kplus/devstack-moonshot,flavio-fernandes/devstack,inkerra/devstack,tianweizhang/devstack,noironetworks/devstack,richliu/devstack,pczerkas/devstack,sc68cal/devstack,sc68cal/devstack,CiscoSystems/devstack,avvocatodemarchis/devstack,CloudServer/devstack,liuquansheng47/devstack,mc2014/devstack,kplus/devstack-moonshot,atulpatil301/devstack,varunarya10/devstack,prithivm/branch01,thomasem/devstack,noironetworks/devstack,j4/devstack,olivierlemasle/devstack,bigswitch/devstack,tianweizhang/devstack,upadhyay-prashant/devstack,samgoon/devstack,andrewrothstein/devstack,costingalan/devstack,prithivm/branch01,ewindisch/raspi-devstack,nuxeh/devstack,sequenceiq/devstack,LoHChina/devstack,parul24/devstack,srics/devstack,thomasem/devstack,TwinkleChawla/devstack,nawawi/openstack,NaokiMiyata/devstack,vishnugonela/devstack,dirkmueller/devstack,eshnil2000/devstack,mssumanth/devstack,vsham20/devstack,ozamiatin/devstack