update gemfile

Author: williamschen23

Gemfile

@@ -0,0 +1,14 @@
+# This should be synced ocasionally with https://pages.github.com/versions/
+source 'https://rubygems.org'
+
+group :jekyll_plugins do
+  gem "github-pages", "232"
+end
+
+gem 'wdm', '>= 0.1.1' if Gem.win_platform?
+
+gem "webrick", "~> 1.9"
+
+gem 'html-proofer', "~> 3.19.4"
+
+gem 'json'