Require Ruby 2.3

Author: DirtyF

.rubocop.yml

@@ -2,7 +2,7 @@ inherit_gem:
   jekyll: .rubocop.yml
 
 AllCops:
-  TargetRubyVersion: 2.1
+  TargetRubyVersion: 2.3
   Exclude:
     - vendor/**/*
     - spec/*.rb

.travis.yml

@@ -10,10 +10,9 @@ rvm:
   - 2.5
   - 2.4
   - 2.3
-  - 2.2
 env:
   - ""
-  - JEKYLL_VERSION=3.7.0
+  - JEKYLL_VERSION=3.8.0
 matrix:
   include:
     - # GitHub Pages

jekyll-gist.gemspec

@@ -14,7 +14,7 @@ Gem::Specification.new do |spec|
   spec.homepage      = "https://github.com/jekyll/jekyll-gist"
   spec.license       = "MIT"
 
-  spec.required_ruby_version = ">= 2.1"
+  spec.required_ruby_version = ">= 2.3.0"
 
   spec.files         = `git ls-files -z`.split("\x0")
   spec.executables   = spec.files.grep(%r!^bin/!) { |f| File.basename(f) }