Make py3pep8 tox target use a general python3.
diff --git a/tox.ini b/tox.ini
index feebf28..7ee4d80 100644
--- a/tox.ini
+++ b/tox.ini
@@ -69,7 +69,7 @@
     flake8 .
 
 [testenv:py3pep8]
-basepython = python3.4
+basepython = python3
 deps =
     flake8
     flake8-import-order