Merge pull request #40 from ruby-korea/39-remove-dead-links

죽은 링크 제거 & 루비 버전업

Author: marocchino

.travis.yml

@@ -2,7 +2,7 @@ sudo: false
 language: ruby
 cache: bundler
 rvm:
-  - 2.5.0
+  - 3.0.0
 branches:
   only:
     - jekyll

Gemfile

@@ -1,10 +1,11 @@
 source "https://rubygems.org"
-ruby '2.5.0' unless ENV['DEV']
+ruby '3.0.0' unless ENV['DEV']
 
 gem 'rake'
 gem 'github-pages'
 gem 'kramdown'
 gem 'travis'
+gem 'webrick'
 
 group :development do
   gem 'validate-website', '~> 1.0'