functional/tester: add "EtcdClientEndpoints" to "Checker"

Signed-off-by: Gyuho Lee <gyuhox@gmail.com>

functional/tester/checker.go

@@ -20,6 +20,9 @@ import "github.com/coreos/etcd/functional/rpcpb"
 type Checker interface {
 	// Type returns the checker type.
 	Type() rpcpb.Checker
+	// EtcdClientEndpoints returns the client endpoints of
+	// all checker target nodes..
+	EtcdClientEndpoints() []string
 	// Check returns an error if the system fails a consistency check.
 	Check() error
 }