fix missing import

Author: bckohan

django_enum/tests/tests.py

@@ -12,7 +12,7 @@
 from django.test import Client, TestCase
 from django.urls import reverse
 from django_enum import TextChoices
-from django_enum.forms import EnumChoiceField
+from django_enum.forms import EnumChoiceField  # dont remove this
 from django_enum.tests.djenum.enums import (
     BigIntEnum,
     BigPosIntEnum,