Updated an import per isort.

tests/forms_tests/field_tests/test_charfield.py

@@ -1,7 +1,8 @@
 from __future__ import unicode_literals
 
 from django.forms import (
-    CharField, HiddenInput, PasswordInput, Textarea, TextInput, ValidationError,
+    CharField, HiddenInput, PasswordInput, Textarea, TextInput,
+    ValidationError,
 )
 from django.test import SimpleTestCase