Increase the suggested minimum ram to 4gb
Increase the suggested minimum ram to 4gb

Change-Id: I4f098d731693e635ebcc89357d382674c7730201

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