TUN-3375: Upgrade coredns and prometheus dependencies

vendor/github.com/opentracing/opentracing-go/ext/field.go

@@ -0,0 +1,17 @@
+package ext
+
+import (
+	"github.com/opentracing/opentracing-go"
+	"github.com/opentracing/opentracing-go/log"
+)
+
+// LogError sets the error=true tag on the Span and logs err as an "error" event.
+func LogError(span opentracing.Span, err error, fields ...log.Field) {
+	Error.Set(span, true)
+	ef := []log.Field{
+		log.Event("error"),
+		log.Error(err),
+	}
+	ef = append(ef, fields...)
+	span.LogFields(ef...)
+}