PEP fixes

InvenTree/build/test_api.py

@@ -5,6 +5,9 @@ from datetime import datetime, timedelta
 
 from django.urls import reverse
 
+from django.contrib.auth import get_user_model
+from django.contrib.auth.models import Group
+
 from rest_framework.test import APITestCase
 from rest_framework import status
 

InvenTree/build/tests.py

@@ -3,6 +3,7 @@ from __future__ import unicode_literals
 
 from django.test import TestCase
 from django.urls import reverse
+
 from django.contrib.auth import get_user_model
 from django.contrib.auth.models import Group