.travis.yml in i18n-js-3.0.10 vs .travis.yml in i18n-js-3.0.11

- old
+ new

@@ -1,11 +1,14 @@
 # Send builds to container-based infrastructure
 # http://docs.travis-ci.com/user/workers/container-based-infrastructure/
 sudo: false
 language: ruby
 cache:
-  - bundler
+  bundler: true
+  yarn: true
+  directories:
+  - node_modules
 rvm:
   - 2.1.10
   - 2.2.8
   # Since the Travis Build Env does not recognize `2.3` alias yet
   # We need to specify the version precisely
@@ -13,10 +16,10 @@
   - 2.4.3
   - 2.5.0
   - ruby-head
 before_install:
 # Need to install something extra to test JS
-- npm install
+- yarn install
 # Bundler 1.16.1 and rubygems 2.7.3 got issue
 # https://github.com/travis-ci/travis-ci/issues/8978#issuecomment-354036443
 - gem update --system
 gemfile:
   - gemfiles/i18n_0_6.gemfile