Add py29 to tox.ini envlist
diff --git a/tox.ini b/tox.ini
index 867f125..8694f6d 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist = py27,pypy,py35,py36,py37,py38
+envlist = py27,pypy,py35,py36,py37,py38,py39
 
 [testenv]
 deps =