CHANGELOG-3.4: add recent Raft and logger changes
CHANGELOG-3.4: add recent Raft and logger changes

Signed-off-by: Gyuho Lee <3454051ee3341eb69bdf6fca40899cdad4d86496@gmail.com>

rnaveiras/etcd,vimalk78/etcd,mqliang/etcd,xiang90/etcd,etcd-io/etcd,mkumatag/etcd,joshix/etcd,coreos/etcd,xiang90/etcd,gyuho/etcd,glevand/coreos--etcd,fanminshi/etcd,cockroachdb/etcd,gyuho/etcd,vimalk78/etcd,ajityagaty/etcd,dannysauer/etcd,lorneli/etcd,sebrandon1/etcd,mqliang/etcd,etcd-io/etcd,mqliang/etcd,ajityagaty/etcd,sinsharat/etcd,bdarnell/etcd,etcd-io/etcd,coreos/etcd,rnaveiras/etcd,joshix/etcd,li-ang/etcd,mkumatag/etcd,ajityagaty/etcd,mkumatag/etcd,bdarnell/etcd,cockroachdb/etcd,sinsharat/etcd,lorneli/etcd,rnaveiras/etcd,sebrandon1/etcd,fanminshi/etcd,li-ang/etcd,dannysauer/etcd,glevand/coreos--etcd