language: ruby
sudo: false
before_install:
  - gem install bundler
bundler_args: --without guard
cache: bundler
rvm:
  - 2.4.1
  - 2.6.5
env:
  global:
    - RUN_ALL_TESTS=true

language: ruby
sudo: false
before_install:
  - gem install bundler
bundler_args: --without guard
cache: bundler
rvm:
  - 2.6.9
  - 3.1.0
env:
  global:
    - RUN_ALL_TESTS=true

Test using more modern ruby versions
Test using more modern ruby versions

Removing 2.4.x (last updated 2020-03-31) and adding 3.1.x (just released 2021-12-25)