Require at least Ruby 3 and Rails 6

.github/workflows/tests.yml

@@ -19,7 +19,6 @@ jobs:
           - macos
           - ubuntu
         ruby:
-          - 2.7
           - 3.0
           - 3.1
           - 3.2

Gemfile.lock

@@ -2,8 +2,8 @@ PATH
   remote: .
   specs:
     active_recall (1.9.0)
-      activerecord (>= 5.2.3, <= 7.1)
-      activesupport (>= 5.2.3, <= 7.1)
+      activerecord (>= 6.0, <= 7.1)
+      activesupport (>= 6.0, <= 7.1)
 
 GEM
   remote: https://rubygems.org/

README.md

@@ -2,7 +2,7 @@
 
 **ActiveRecall** is a spaced-repetition system that allows you to treat arbitrary [ActiveRecord](https://github.com/rails/rails/tree/master/activerecord) models as if they were flashcards to be learned and reviewed.
 It it based on, and is intended to be backwards compatible with, the [okubo](https://github.com/rgravina/okubo) gem.
-The primary differentiating features are that it lets the user specify the scheduling algorithm and is fully compatible with Rails 6+ and Ruby 3+.
+The primary differentiating features are that it lets the user specify the scheduling algorithm and is fully compatible with (and requires) Rails 6+ and Ruby 3+.
 
 ## Installation
 

active_recall.gemspec

@@ -36,7 +36,7 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency "rdoc"
   spec.add_development_dependency "rspec", ">= 3.0"
   spec.add_development_dependency "sqlite3"
-  spec.add_runtime_dependency "activerecord", ">= 5.2.3", "<= 7.1"
-  spec.add_runtime_dependency "activesupport", ">= 5.2.3", "<= 7.1"
-  spec.required_ruby_version = ">= 2.6"
+  spec.add_runtime_dependency "activerecord", ">= 6.0", "<= 7.1"
+  spec.add_runtime_dependency "activesupport", ">= 6.0", "<= 7.1"
+  spec.required_ruby_version = ">= 3.0"
 end