Linting

Signed-off-by: Emmy D'Anello <emmy.danello@animath.fr>

registration/tests.py

@@ -7,7 +7,6 @@ from django.contrib.auth.models import User
 from django.contrib.contenttypes.models import ContentType
 from django.contrib.sites.models import Site
 from django.core.files.uploadedfile import SimpleUploadedFile
-from django.core.management import call_command
 from django.test import TestCase
 from django.urls import reverse
 from django.utils.encoding import force_bytes