config.yml in longleaf-1.1.0

- old
+ new

@@ -76,10 +76,10 @@
       - install_new_bundler
       - build_and_run_tests
 
   test_with_ruby_latest:
     docker:
-      - image: circleci/ruby:latest
+      - image: circleci/ruby:2.7
         environment:
           BUNDLER_VERSION: 2.1.4
 
     working_directory: ~/repo
 