Test: No trace id in Trace

[hanahmily]

Refer to #1710

Requst

Query

  query BasicTraces($condition: TraceQueryCondition) {
    queryBasicTraces(condition: $condition) {
      traces {
        key: segmentId
        endpointNames
        duration
        start
        isError
        traceIds
      }
      total
    }
  }

Variables

{"condition":{"traceState":"ALL","queryOrder":"BY_START_TIME","queryDuration":{"start":"2018-10-10 1100","end":"2018-10-10 1115","step":"MINUTE"},"paging":{"pageNum":1,"pageSize":20,"needTotal":true}}

Response

{"data":{"queryBasicTraces":{"traces":[{"key":"4.5.6","endpointNames":["org.apache.skywalking.RocketMQ"],"duration":2000,"start":"1539140634654","isError":false,"traceIds":[]},{"key":"7.8.9","endpointNames":["org.skywaking.apm.testcase.dubbo.services.GreetService.doBusiness()"],"duration":2000,"start":"1539140634654","isError":true,"traceIds":[]},{"key":"16.17.18","endpointNames":["org.skywaking.apm.testcase.dubbo.services.GreetService.doBusiness()"],"duration":2000,"start":"1539140634654","isError":true,"traceIds":[]},{"key":"13.14.15","endpointNames":["org.apache.skywalking.RocketMQ"],"duration":2000,"start":"1539140634654","isError":true,"traceIds":[]}],"total":4}}}