test(travis): add yarn install step

jeffbcross · jeffbcross · commit d5e516037141 · 2016-11-01T10:23:57.000-07:00
diff --git a/.travis.yml b/.travis.yml
@@ -19,7 +19,8 @@ env:
   - CXX=g++-4.8
 
 install:
-  - npm install
+  - npm install -g yarn
+  - yarn install
 
 before_script:
   - export DISPLAY=:99.0
