Update Ruby

.gitignore

@@ -3,3 +3,4 @@ _site
 .jekyll-cache
 .jekyll-metadata
 vendor
+public

.gitlab-ci.yml

 pages:
   stage: deploy
-  image: ruby:2.7
+  image: ruby:3.0
   script:
     - gem install bundler
     - bundle install

Gemfile.lock

 GEM
   remote: https://rubygems.org/
   specs:
-    addressable (2.7.0)
+    addressable (2.8.0)
       public_suffix (>= 2.0.2, < 5.0)
     colorator (1.1.0)
-    concurrent-ruby (1.1.8)
+    concurrent-ruby (1.1.9)
     em-websocket (0.5.2)
       eventmachine (>= 0.12.9)
       http_parser.rb (~> 0.6.0)
     eventmachine (1.2.7)
-    ffi (1.15.1)
+    ffi (1.15.3)
     forwardable-extended (2.6.0)
     http_parser.rb (0.6.0)
     i18n (1.8.10)