Update the Gemfile to run on newer rubies

Author: rtyler

Gemfile

@@ -1,18 +1,21 @@
 source "https://rubygems.org"
 
-gem "jekyll", "~> 3.8.5"
+#gem "jekyll", "~> 4.0"
 gem 'kramdown'
 gem 'rouge'
 
 # If you want to use GitHub Pages, remove the "gem "jekyll"" above and
 # uncomment the line below. To upgrade, run `bundle update github-pages`.
-gem "github-pages", "~> 201", group: :jekyll_plugins
+gem "github-pages", group: :jekyll_plugins
 
 # If you have any plugins, put them here!
 group :jekyll_plugins do
-  gem "jekyll-feed", "~> 0.11"
+  gem "jekyll-feed"
+  gem 'jekyll-paginate'
 end
 
+gem 'webrick'
+
 # Windows and JRuby does not include zoneinfo files, so bundle the tzinfo-data gem
 # and associated library.
 install_if -> { RUBY_PLATFORM =~ %r!mingw|mswin|java! } do