Upgrade Python syntax with pyupgrade --py3-plus

testing/test_dsession.py

@@ -203,7 +203,7 @@ class TestLoadScheduling:
         different test ids are collected by workers.
         """
 
-        class CollectHook(object):
+        class CollectHook:
             """
             Dummy hook that stores collection reports.
             """

testing/test_slavemanage.py

@@ -1,4 +1,3 @@
-from __future__ import print_function
 import py
 import pytest
 import textwrap
@@ -35,7 +34,7 @@ def mysetup(tmpdir):
 
 @pytest.fixture
 def workercontroller(monkeypatch):
-    class MockController(object):
+    class MockController:
         def __init__(self, *args):
             pass