deps: Target Ruby 2.4

Author: DirtyF

.rubocop.yml

@@ -6,6 +6,6 @@ inherit_gem:
   rubocop-jekyll: .rubocop.yml
 
 AllCops:
-  TargetRubyVersion: 2.3
+  TargetRubyVersion: 2.4
   Exclude:
     - vendor/**/*

jekyll-compose.gemspec

@@ -17,7 +17,7 @@ Gem::Specification.new do |spec|
   spec.files         = `git ls-files -z`.split("\x0").grep(%r!^lib/!)
   spec.require_paths = ["lib"]
 
-  spec.required_ruby_version = ">= 2.3.0"
+  spec.required_ruby_version = ">= 2.4.0"
 
   spec.add_dependency "jekyll", ">= 3.7", "< 5.0"