README.md in apicco-sdk-0.1.1 vs README.md in apicco-sdk-0.1.2

@@ -10,9 +10,13 @@
 POST /api/movies.list        api.movies_list
 POST /api/movies.update      api.movies_update(movie_id: 42, title: 'Bar')
 POST /api/movies.delete      api.movies_delete(movie_id: 42)
 ```
 
+## Prerequisites
+
+- Ruby version >= 2.6 (use rvm https://rvm.io/rvm/basics)
+
 ## Usage
 
 ```ruby
 > require 'apicco-sdk'
 > token = 'deadbeef'