CONTRIBUTING.md in indieweb-endpoints-3.0.0 vs CONTRIBUTING.md in indieweb-endpoints-4.0.0

@@ -6,12 +6,12 @@
 1. Review open [pull requests][pulls].
 1. Report a new [issue][issues]. _Only do this after you've made sure the behavior or problem you're observing isn't already documented in an open issue._
 
 ## Getting Started
 
-indieweb-endpoints-ruby is developed using Ruby 2.4.10 and is additionally tested against Ruby 2.5, 2.6, and 2.7 using [Travis CI](https://travis-ci.com/indieweb/indieweb-endpoints-ruby).
+indieweb-endpoints-ruby is developed using Ruby 2.5.8 and is additionally tested against Ruby 2.6 and 2.7 using [Travis CI](https://travis-ci.com/indieweb/indieweb-endpoints-ruby).
 
-Before making changes to indieweb-endpoints-ruby, you'll want to install Ruby 2.4.10. It's recommended that you use a Ruby version managment tool like [rbenv](https://github.com/rbenv/rbenv), [chruby](https://github.com/postmodern/chruby), or [rvm](https://github.com/rvm/rvm). Once you've installed Ruby 2.4.10 using your method of choice, install the project's gems by running:
+Before making changes to indieweb-endpoints-ruby, you'll want to install Ruby 2.5.8. It's recommended that you use a Ruby version managment tool like [rbenv](https://github.com/rbenv/rbenv), [chruby](https://github.com/postmodern/chruby), or [rvm](https://github.com/rvm/rvm). Once you've installed Ruby 2.5.8 using your method of choice, install the project's gems by running:
 
 ```sh
 bundle install
 ```