auth: add del functions for user/role
auth: add del functions for user/role

endocode/etcd,insequent/etcd,chipironcin/etcd,glevand/coreos--etcd,ajityagaty/etcd,coreos/etcd,YuleiXiao/etcd,qqsun8819/etcd,vimalk78/etcd,glevand/coreos--etcd,mickep76/etcd,glycerine/etcd,sebrandon1/etcd,mqliang/etcd,nekto0n/etcd,wantonsolutions/dinv-etcd,glycerine/etcd,lumjjb/etcd,cockroachdb/etcd,wantonsolutions/dinv-etcd,swingbach/etcd,YuleiXiao/etcd,armstrongli/etcd,CrazyJvm/etcd,dannysauer/etcd,chipironcin/etcd,gyuho/etcd,jlamillan/etcd,sofuture/etcd,OyTao/etcd_learning,luxas/etcd,mqliang/etcd,etcd-io/etcd,nekto0n/etcd,handsomesun/etcd,lorneli/etcd,hongchaodeng/etcd,akauppi/etcd,rnaveiras/etcd,lumjjb/etcd,cockroachdb/etcd,visheshnp/etcd,linuxcer/etcd,ravigadde/etcd,jlamillan/etcd,sebrandon1/etcd,tguangch/etcd,heyitsanthony/etcd,endocode/etcd,westhood/etcd,joshix/etcd,rchicoli/etcd,wantonsolutions/dinv-etcd,xiang90/etcd,fanminshi/etcd,swingbach/etcd,li-ang/etcd,etcd-io/etcd,plasticbox/etcd,qqsun8819/etcd,ktateish/etcd,purpleidea/etcd,mickep76/etcd,StorReduce/etcd,coreos/etcd,ktateish/etcd,whuwxl/etcd,hongchaodeng/etcd,plasticbox/etcd,li-ang/etcd,whuwxl/etcd,StorReduce/etcd,gyuho/etcd,OyTao/etcd_learning,a-robinson/etcd,ajityagaty/etcd,purpleidea/etcd,xiang90/etcd,visheshnp/etcd,akauppi/etcd,dannysauer/etcd,fanminshi/etcd,bdarnell/etcd,westhood/etcd,bluebreezecf/etcd,jonboulle/etcd,mkumatag/etcd,linuxcer/etcd,rnaveiras/etcd,luxas/etcd,CrazyJvm/etcd,etcd-io/etcd,insequent/etcd,rnaveiras/etcd,sinsharat/etcd,jonboulle/etcd,yudai/etcd,yudai/etcd,armstrongli/etcd,lorneli/etcd,mkumatag/etcd,sinsharat/etcd,rchicoli/etcd,a-robinson/etcd,handsomesun/etcd,joshix/etcd,ravigadde/etcd,bluebreezecf/etcd,bdarnell/etcd,zaphod-concur/etcd,zaphod-concur/etcd,vimalk78/etcd,mqliang/etcd,mkumatag/etcd,ajityagaty/etcd,tguangch/etcd,sofuture/etcd,heyitsanthony/etcd