Merge pull request #12116 from mtnbikenc/tox-python

Refine Python version for tox in travis

tox.ini

@@ -1,6 +1,6 @@
 [tox]
 envlist =
-    py3-{flake8,pylint,yamllint,ansible_syntax}
+    py36-{flake8,pylint,yamllint,ansible_syntax}
 skipsdist=True
 skip_missing_interpreters=True