dropped python 2.7 compat codes from tests

tests/browsable_api/auth_urls.py

@@ -1,5 +1,3 @@
-from __future__ import unicode_literals
-
 from django.conf.urls import include, url
 
 from .views import MockView

tests/browsable_api/no_auth_urls.py

@@ -1,5 +1,3 @@
-from __future__ import unicode_literals
-
 from django.conf.urls import url
 
 from .views import MockView

tests/browsable_api/test_browsable_api.py

@@ -1,5 +1,3 @@
-from __future__ import unicode_literals
-
 from django.contrib.auth.models import User
 from django.test import TestCase, override_settings
 

tests/browsable_api/test_browsable_nested_api.py

@@ -1,5 +1,3 @@
-from __future__ import unicode_literals
-
 from django.conf.urls import url
 from django.test import TestCase
 from django.test.utils import override_settings

tests/browsable_api/views.py

@@ -1,5 +1,3 @@
-from __future__ import unicode_literals
-
 from rest_framework import authentication, renderers
 from rest_framework.response import Response
 from rest_framework.views import APIView