Remove Python 2 support

tests/test_auth.py

@@ -1,8 +1,6 @@
-# -*- coding: utf-8 -*-
-#
 # This file is part of Radicale Server - Calendar Server
 # Copyright © 2012-2013 Guillaume Ayoub
-# Copyright © 2012-2013 Jean-Marc Martins
+# Copyright © 2012-2016 Jean-Marc Martins
 #
 # This library is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -27,9 +25,11 @@ import hashlib
 import os
 import radicale
 import tempfile
+
 from radicale import config
 from radicale.auth import htpasswd
-from tests import BaseTest
+
+from . import BaseTest
 
 
 class TestBaseAuthRequests(BaseTest):