Merge pull request scala-js#11 from exoego/ci-failing

Attempt to fix CI failing

Author: exoego

.travis.yml

@@ -21,7 +21,7 @@ script:
 cache:
   directories:
     - $HOME/.ivy2/cache
-    - $HOME/.sbt
+    - $HOME/.sbt/boot
     - $HOME/.cache/coursier
 before_cache:
   - rm -fv $HOME/.ivy2/.sbt.ivy.lock