Refine .travis.yml

robertodr · robertodr · commit ac068b91348c · 2017-09-30T19:02:40.000+02:00
diff --git a/.travis.yml b/.travis.yml
@@ -4,7 +4,7 @@ dist: trusty
 os: linux
 ruby: 2.2.0
 before_script:
-- pip install yapf
+- pip install --upgrade pip yapf futures
 - bundle install
 script:
 - bundle exec danger
