Refs #23919 -- Removed encoding preambles and future imports

tests/migrations/test_writer.py

@@ -1,6 +1,3 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
 import datetime
 import decimal
 import functools
@@ -662,7 +659,6 @@ class WriterTests(SimpleTestCase):
 
         self.assertTrue(
             output.startswith(
-                "# -*- coding: utf-8 -*-\n"
                 "# Generated by Django %(version)s on 2015-07-31 04:40\n" % {
                     'version': get_version(),
                 }