Add yarn cache to travis

diff --git a/.travis.yml b/.travis.yml
index 5c6302bc930529bd30ddc73759f831a7f4d431a6..7b8935a323030c28c64b3f62f4aca07f586bef31 100644 (file)
--- a/.travis.yml
+++ b/.travis.yml
@@ -14,6 +14,8 @@ addons:
       - g++-4.8
   postgresql: "9.4"
 
+cache: yarn
+
 sudo: false
 
 services: