Accepts zipkin2 json span format

[codefromthecrypt]

This uses the recently released detecting decoder to support the new
Span2 format defined in openzipkin/zipkin#1499

[codefromthecrypt]

verified with an ad-hoc client:

  @Test
  public void test() throws Exception {
    EventData sendEvent = new EventData(("[{\n"
        + "  \"traceId\": \"86154a4ba6e91388\",\n"
        + "  \"id\": \"86154a4ba6e91387\",\n"
        + "  \"kind\": \"SERVER\",\n"
        + "  \"name\": \"get\",\n"
        + "  \"timestamp\": 1502678423123456,\n"
        + "  \"duration\": 207000,\n"
        + "  \"localEndpoint\": {\n"
        + "    \"serviceName\": \"testservice\",\n"
        + "    \"ipv4\": \"113.210.108.10\"\n"
        + "  },\n"
        + "  \"tags\": {\n"
        + "    \"http.path\": \"/api/blah\"\n"
        + "  }\n"
        + "}]").getBytes(Util.UTF_8));

    String connectString = new ConnectionStringBuilder(
        "zipkin",
        "zipkin",
        "RootManageSharedAccessKey",
        "Aint Tellin"
    ).toString();
    EventHubClient.createFromConnectionStringSync(connectString).sendSync(sendEvent);
  }