README.md in navigator-2.1.0 vs README.md in navigator-2.2.0

@@ -68,10 +68,10 @@
 - Provides `link`, `image`, and `item` convenience methods for succinct ways to build commonly used
   menu elements.
 
 # Requirements
 
-0. [Ruby 2.x.x](https://www.ruby-lang.org).
+0. [Ruby 2.4.x](https://www.ruby-lang.org).
 0. [Ruby on Rails 5.x.x](http://rubyonrails.org).
 
 # Setup
 
 For a secure install, type the following from the command line (recommended):