Use goose for migrations

postgres/models.go

@@ -13,10 +13,10 @@ type Budget struct {
 }
 
 type User struct {
-	ID       sql.NullString
-	Email    sql.NullString
-	Name     sql.NullString
-	Password sql.NullString
+	ID       string
+	Email    string
+	Name     string
+	Password string
 }
 
 type UserBudget struct {