add metrics test
add metrics test

hw-qiaolei/skydns,tonicbupt/skydns,nicescale/skydns,yonglehou/skydns,weekface/skydns,skynetservices/skydns,zhang0137/skydns,andrewrothstein/skydns,no2key/skydns,netf/skydns,vinhhrv/skydns,loveshell/skydns,tuannvm/skydns,AdoHe/skydns,ZeaLoVe/skydns