replace flake8-import-order by isort

tests/test_connection_mongomock.py

@@ -3,15 +3,9 @@ import unittest
 import pytest
 
 import mongoengine.connection
-from mongoengine import (
-    Document,
-    StringField,
-    connect,
-    disconnect_all,
-)
+from mongoengine import connect, disconnect_all, Document, StringField
 from mongoengine.connection import get_connection
 
-
 try:
     import mongomock