fixes tests for renamed SortedDict

tests/test_fields.py

@@ -11,13 +11,9 @@ from django.core import validators
 from django.db import models
 from django.test import TestCase
 from rest_framework import serializers
+from rest_framework.compat import SortedDict
 from tests.models import RESTFrameworkModel
 
-try:
-    from collections import OrderedDict
-except ImportError:
-    from django.utils.datastructures import SortedDict as OrderedDict
-
 
 class TimestampedModel(models.Model):
     added = models.DateTimeField(auto_now_add=True)
@@ -99,7 +95,7 @@ class BasicFieldTests(TestCase):
         Field should preserve dictionary ordering, if it exists.
         See: https://github.com/tomchristie/django-rest-framework/issues/832
         """
-        ret = OrderedDict()
+        ret = SortedDict()
         ret['c'] = 1
         ret['b'] = 1
         ret['a'] = 1

tests/test_serializer.py

@@ -1312,7 +1312,7 @@ class SerializerPickleTests(TestCase):
         Regression test for #645.
         """
         data = serializers.DictWithMetadata({1: 1})
-        self.assertEqual(data.__getstate__(), serializers.OrderedDict({1: 1}))
+        self.assertEqual(data.__getstate__(), serializers.SortedDict({1: 1}))
 
     def test_serializer_data_is_pickleable(self):
         """