Remove six library

testing/conftest.py

@@ -1,20 +1,9 @@
-import six
 import py
 import pytest
 import execnet
 
 pytest_plugins = "pytester"
 
-if six.PY2:
-
-    @pytest.fixture(scope="session", autouse=True)
-    def _ensure_imports():
-        # we import some modules because pytest-2.8's testdir fixture
-        # will unload all modules after each test and this cause
-        # (unknown) problems with execnet.Group()
-        execnet.Group
-        execnet.makegateway
-
 
 @pytest.fixture(autouse=True)
 def _divert_atexit(request, monkeypatch):