print out git references for trees
print out git references for trees

in order to be sure we understand the environment that's running
in an upstream test, print out the git information for the tree.
This will hopefully address questions of "which commit of tempest"
is being used for particular tests.

Change-Id: Ief4e8a17fd75945f02982d2adf8625fe927d823d

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