From c03e86be5aa2f041255e359db61ad43ad76e1248 Mon Sep 17 00:00:00 2001
From: Tianhao He <tianhao64@users.noreply.github.com>
Date: Fri, 28 Apr 2017 14:57:39 -0700
Subject: [PATCH] update travis-ci file

Signed-off-by: Tianhao He <tianhao64@users.noreply.github.com>
---
 .travis.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.travis.yml b/.travis.yml
index ad0a4fd1..72b09a0b 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,7 +4,7 @@ python:
   - "3.6"
 # command to install dependencies
 install: 
-  - pip install -r requirements.txt
+  - pip install -r requirements.txt --upgrade --ignore-installed six
   - pip install -r test-requirements.txt
   - pip install pycodestyle
 # command to run tests