upgrade go module v2

datastructure/link/doublylink.go

@@ -4,7 +4,7 @@ import (
 	"errors"
 	"fmt"
 
-	"github.com/duke-git/lancet/datastructure"
+	"github.com/duke-git/lancet/v2/datastructure"
 )
 
 // DoublyLink is a linked list. Whose node has a generic Value, Pre pointer points to a previous node of the link, Next pointer points to a next node of the link.

datastructure/link/doublylink_test.go

@@ -3,7 +3,7 @@ package datastructure
 import (
 	"testing"
 
-	"github.com/duke-git/lancet/internal"
+	"github.com/duke-git/lancet/v2/internal"
 )
 
 func TestDoublyLink_InsertAtFirst(t *testing.T) {

datastructure/link/singlylink.go

@@ -4,7 +4,7 @@ import (
 	"errors"
 	"fmt"
 
-	"github.com/duke-git/lancet/datastructure"
+	"github.com/duke-git/lancet/v2/datastructure"
 )
 
 // SinglyLink is a linked list. Whose node has a Value generics and Next pointer points to a next node of the link.

datastructure/link/singlylink_test.go

@@ -3,7 +3,7 @@ package datastructure
 import (
 	"testing"
 
-	"github.com/duke-git/lancet/internal"
+	"github.com/duke-git/lancet/v2/internal"
 )
 
 func TestSinglyLink_InsertAtFirst(t *testing.T) {