Revert "Implement notifies for transfer plugin (#3972)" (#3995)

This reverts commit 68f1dd5ddf.

Signed-off-by: Yong Tang <yong.tang.github@outlook.com>

plugin/transfer/select_test.go

@@ -1,58 +0,0 @@
-package transfer
-
-import (
-	"context"
-	"fmt"
-	"testing"
-
-	"github.com/coredns/coredns/plugin/pkg/dnstest"
-	"github.com/coredns/coredns/plugin/test"
-
-	"github.com/miekg/dns"
-)
-
-type (
-	t1 struct{}
-	t2 struct{}
-)
-
-func (t t1) Transfer(zone string, serial uint32) (<-chan []dns.RR, error) {
-	const z = "example.org."
-	if zone != z {
-		return nil, ErrNotAuthoritative
-	}
-	return nil, fmt.Errorf(z)
-}
-func (t t2) Transfer(zone string, serial uint32) (<-chan []dns.RR, error) {
-	const z = "sub.example.org."
-	if zone != z {
-		return nil, ErrNotAuthoritative
-	}
-	return nil, fmt.Errorf(z)
-}
-
-func TestZoneSelection(t *testing.T) {
-	tr := &Transfer{
-		Transferers: []Transferer{t1{}, t2{}},
-		xfrs: []*xfr{
-			{
-				Zones: []string{"example.org."},
-				to:    []string{"192.0.2.1"}, // RFC 5737 IP, no interface should have this address.
-			},
-			{
-				Zones: []string{"sub.example.org."},
-				to:    []string{"*"},
-			},
-		},
-	}
-	r := new(dns.Msg)
-	r.SetAxfr("sub.example.org.")
-	w := dnstest.NewRecorder(&test.ResponseWriter{})
-	_, err := tr.ServeDNS(context.TODO(), w, r)
-	if err == nil {
-		t.Fatal("Expected error, got nil")
-	}
-	if x := err.Error(); x != "sub.example.org." {
-		t.Errorf("Expected transfer for zone %s, got %s", "sub.example.org", x)
-	}
-}