From 6e1a8f6ed992829228533fcec3a056a87448f993 Mon Sep 17 00:00:00 2001
From: Pete Jemian <prjemian@gmail.com>
Date: Mon, 13 May 2019 11:55:49 -0500
Subject: [PATCH] #660

---
 .travis.yml | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/.travis.yml b/.travis.yml
index 7781ec146b..7dfa1a2cab 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,10 +5,13 @@
 # for advice, see:
 #  https://docs.travis-ci.com/user/customizing-the-build#The-Build-Lifecycle
 
+dist: xenial   # required for Python >= 3.7
 language: python
 python:
   - "2.7"
   - "3.5"
+  - "3.6"
+  - "3.7"
 
 install:
   - pip install lxml six sphinx