Centralize Ruby Version to .ruby-version

The `.ruby-version` file is the ecosystem standard for defining a Ruby
version. This commit adds the `.ruby-version` file and removes all other
references as they will read from this file.

.github/workflows/ci.yml

@@ -11,7 +11,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: [ 2.7.1, 3.2.1 ]
+        ruby: [ 3.0, 3.1, 3.2 ]
     name: Test Ruby ${{ matrix.ruby }}
     steps:
       - uses: actions/checkout@v4

.rubocop.yml

@@ -2,7 +2,6 @@ inherit_gem:
   rubocop-shopify: rubocop.yml
 
 AllCops:
-  TargetRubyVersion: 2.6.4
   Exclude:
     - vendor/**/*
   UseCache: true

.ruby-version

@@ -0,0 +1 @@
+3.2.1

dev.yml

@@ -2,7 +2,7 @@
 name: recordstore
 
 up:
-  - ruby: 3.2.1
+  - ruby
   - bundler
 
 commands:

record_store.gemspec

@@ -24,7 +24,7 @@ Gem::Specification.new do |spec|
   spec.executables = ['record-store']
   spec.require_paths = ['lib']
 
-  spec.required_ruby_version = '>= 2.0'
+  spec.required_ruby_version = '>= 3.0.0'
 
   spec.add_runtime_dependency 'activemodel', '>= 4.2'
   spec.add_runtime_dependency 'activesupport', '>= 4.2'