A couple of isort fixes

wagtail/contrib/modeladmin/tests/test_page_modeladmin.py

@@ -4,9 +4,9 @@ from django.contrib.auth import get_user_model
 from django.contrib.auth.models import Group
 from django.test import TestCase
 
-from wagtail.wagtailcore.models import Page
 from wagtail.tests.testapp.models import BusinessIndex
 from wagtail.tests.utils import WagtailTestUtils
+from wagtail.wagtailcore.models import Page
 
 
 class TestIndexView(TestCase, WagtailTestUtils):

wagtail/contrib/modeladmin/tests/test_simple_modeladmin.py

@@ -4,7 +4,7 @@ from django.contrib.auth import get_user_model
 from django.contrib.auth.models import Group
 from django.test import TestCase
 
-from wagtail.tests.modeladmintest.models import Book, Author
+from wagtail.tests.modeladmintest.models import Author, Book
 from wagtail.tests.utils import WagtailTestUtils