Align tox.ini with .travis.yml
diff --git a/tox.ini b/tox.ini
index bf2eba2..9dd4c2f 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,7 +1,7 @@
 [tox]
 project = pre_commit_hooks
 # These should match the travis env list
-envlist = py27,py34,py35,pypy
+envlist = py27,py35,py36,pypy
 
 [testenv]
 deps = -rrequirements-dev.txt