Add Python 3 Train unit tests
This is a mechanically generated patch to ensure unit testing is in place
for all of the Tested Runtimes for Train.
See the Train python3-updates goal document for details:
https://governance.openstack.org/tc/goals/train/python3-updates.html
Change-Id: Icd848acb737e046e76e5496f3acd02e1437b7349
diff --git a/tox.ini b/tox.ini
index e2cc8df..9681d17 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,6 +1,6 @@
[tox]
minversion = 2.0
-envlist = py36,py35,py27,pypy,pep8
+envlist = py37,py36,py27,pypy,pep8
skipsdist = True
[testenv]