Drop support for Ruby 2.3

.github/workflows/test.yml

@@ -53,7 +53,7 @@ jobs:
       matrix:
         gemfile: ['rails_5.2', 'rails_6.0', 'rails_6.1', 'rails_7.0']
 
-        ruby: ['2.3', '2.4', '2.5', '2.6', '2.7', '3.0']
+        ruby: ['2.4', '2.5', '2.6', '2.7', '3.0']
 
         client: ['active_record', 'redis']
 
@@ -63,17 +63,11 @@ jobs:
           - ruby: '3.0'
             gemfile: 'rails_5.2'
           # Rails >= 6 requires Ruby >= 2.5
-          - ruby: '2.3'
-            gemfile: 'rails_6.0'
           - ruby: '2.4'
             gemfile: 'rails_6.0'
-          - ruby: '2.3'
-            gemfile: 'rails_6.1'
           - ruby: '2.4'
             gemfile: 'rails_6.1'
           # Rails >= 7 requires Ruby >= 2.7
-          - ruby: '2.3'
-            gemfile: 'rails_7.0'
           - ruby: '2.4'
             gemfile: 'rails_7.0'
           - ruby: '2.5'

.rubocop.yml

@@ -6,7 +6,7 @@ AllCops:
   Exclude:
     - lib/generators/**/*
     - vendor/bundle/**/*
-  TargetRubyVersion: 2.3
+  TargetRubyVersion: 2.4
 
 Layout/LineLength:
   Enabled: false

rpush.gemspec

@@ -22,7 +22,7 @@ Gem::Specification.new do |s|
   s.executables   = `git ls-files -- bin`.split("\n").map { |f| File.basename(f) }
   s.require_paths = ["lib"]
 
-  s.required_ruby_version = '>= 2.3.0'
+  s.required_ruby_version = '>= 2.4.0'
 
   s.post_install_message = <<~POST_INSTALL_MESSAGE
     When upgrading Rpush, don't forget to run `bundle exec rpush init` to get all the latest migrations.