Documentation: del backward_compatibility from v3
Documentation: del backward_compatibility from v3

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