Fix CheckoutReadView test

kfet/tests/test_views.py

@@ -4,6 +4,7 @@ from decimal import Decimal
 from unittest import mock
 
 from django.contrib.auth.models import Group
+from django.core.serializers.json import DjangoJSONEncoder
 from django.core.urlresolvers import reverse
 from django.test import Client, TestCase
 from django.utils import timezone
@@ -790,18 +791,23 @@ class CheckoutReadViewTests(ViewTestCaseMixin, TestCase):
 
         self.assertEqual(r.status_code, 200)
         content = json.loads(r.content.decode('utf-8'))
+        json_now = json.dumps(self.now, cls=DjangoJSONEncoder).strip('"')
+        json_tomorrow = json.dumps(
+            self.now + timedelta(days=1),
+            cls=DjangoJSONEncoder
+        ).strip('"')
 
         self.assertEqual(content, {
             'id': self.checkout.pk,
             'name': 'Checkout',
-            'balance': '0.00',
-            'valid_from': '2018-01-12T16:20:00Z',
-            'valid_to': '2018-01-17T16:20:00Z',
+            'balance': '10.00',
+            'valid_from': json_now,
+            'valid_to': json_tomorrow,
             'laststatement': {
                 'id': self.checkout.statements.all()[0].pk,
-                'at': '2018-01-12T16:20:00Z',
-                'balance_new': '0.00',
-                'balance_old': '0.00',
+                'at': json_now,
+                'balance_new': '10.00',
+                'balance_old': '10.00',
                 'by': str(self.accounts['team']),
             },
         })