update one requirement

aliciawyy · aliciawyy · commit 8883b271e823 · 2017-07-29T17:27:46.000+02:00
diff --git a/.travis.yml b/.travis.yml
@@ -18,7 +18,7 @@ cache:
   - pip
 
 install:
-  - travis_retry pip install -q coveralls codecov
+  - travis_retry pip install -q coveralls codecov six
   - pip install flake8  # eventually worth
 
 script:
