mvcc: add range benchmark for fetching 100 keys
mvcc: add range benchmark for fetching 100 keys

sebrandon1/etcd,glevand/coreos--etcd,cockroachdb/etcd,a-robinson/etcd,akauppi/etcd,glevand/coreos--etcd,heyitsanthony/etcd,etcd-io/etcd,visheshnp/etcd,mickep76/etcd,joshix/etcd,ajityagaty/etcd,mqliang/etcd,ajityagaty/etcd,visheshnp/etcd,xiang90/etcd,rnaveiras/etcd,mkumatag/etcd,etcd-io/etcd,mkumatag/etcd,whuwxl/etcd,ajityagaty/etcd,mkumatag/etcd,YuleiXiao/etcd,akauppi/etcd,heyitsanthony/etcd,dannysauer/etcd,vimalk78/etcd,rnaveiras/etcd,dannysauer/etcd,fanminshi/etcd,coreos/etcd,bluebreezecf/etcd,lorneli/etcd,bdarnell/etcd,rnaveiras/etcd,lorneli/etcd,YuleiXiao/etcd,mickep76/etcd,joshix/etcd,sinsharat/etcd,mqliang/etcd,whuwxl/etcd,fanminshi/etcd,cockroachdb/etcd,mqliang/etcd,a-robinson/etcd,sebrandon1/etcd,etcd-io/etcd,gyuho/etcd,coreos/etcd,gyuho/etcd,li-ang/etcd,xiang90/etcd,bdarnell/etcd,sinsharat/etcd,bluebreezecf/etcd,li-ang/etcd,vimalk78/etcd