fix: function names

domain/entity/book/interface.go

@@ -16,13 +16,13 @@ type Writer interface {
 	Delete(id entity.ID) error
 }
 
-//Repository repository interface
-type Repository interface {
+//repository interface
+type repository interface {
 	Reader
 	Writer
 }
 
 //Manager interface
 type Manager interface {
-	Repository
+	repository
 }

domain/entity/book/manager.go

@@ -8,11 +8,11 @@ import (
 )
 
 type manager struct {
-	repo Repository
+	repo repository
 }
 
 //NewManager create new manager
-func NewManager(r Repository) *manager {
+func NewManager(r repository) *manager {
 	return &manager{
 		repo: r,
 	}