.circleci/config.yml in ws-style-0.2.0 vs .circleci/config.yml in ws-style-0.4.0

@@ -2,13 +2,16 @@
 # Check https://circleci.com/docs/2.0/language-ruby/ for more details
 version: 2
 jobs:
   build:
     docker:
-       - image: circleci/ruby:2.4.1
+       - image: circleci/ruby:2.5.3
     working_directory: ~/repo
     steps:
       - checkout
       - run: bundle install --jobs=4 --retry=3 --path vendor/bundle
       - run: bundle exec bundle-audit update && bundle exec bundle-audit check
       - run: bundle exec rubocop --config=default.yml
+      - run:
+          name: Check default.yml for warnings
+          command: "! bundle exec rubocop --config=default.yml 2>&1 | grep 'Warning:'"
       - run: bundle exec rspec