Use urandom rather than openssl for password gen
Use urandom rather than openssl for password gen

I tried using devstack on a cloud image that didn't have openssl, so
it generated blank passwords and gave an error about openssl missing.
Using urandom should not require more than minimal shell tools.

Change-Id: Ib3091183eb1d85fc8cf7c76e47da24a04ae4791f

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