.travis.yml in tree_branch-1.1.0 vs .travis.yml in tree_branch-1.1.1

@@ -3,18 +3,23 @@
     - CC_TEST_REPORTER_ID=3f49ba7a3ab8a835b5bba9f0932adaba5996dbffde7c098b20d52a3eaa833757
 language: ruby
 rvm:
   # Build on the latest stable of all supported Rubies (https://www.ruby-lang.org/en/downloads/):
   - 2.3.8
-  - 2.4.5
-  - 2.5.3
-  - 2.6.0
+  - 2.4.6
+  - 2.5.5
+  - 2.6.3
 cache: bundler
 before_script:
   - curl -L https://codeclimate.com/downloads/test-reporter/test-reporter-latest-linux-amd64 > ./cc-test-reporter
   - chmod +x ./cc-test-reporter
   - ./cc-test-reporter before-build
 script:
   - bundle exec rubocop
   - bundle exec rspec
 after_script:
   - ./cc-test-reporter after-build --exit-code $TRAVIS_TEST_RESULT
+addons:
+  # https://docs.travis-ci.com/user/uploading-artifacts/
+  artifacts:
+    paths:
+      - Gemfile.lock