Update dependencies (#3245)

* Update dependencies

* Remove more things we don't need

Gemfile

@@ -3,18 +3,9 @@ source "https://rubygems.org"
 group :development do
   gem 'rake', '~> 10.0'
   gem 'jekyll', '~> 3.0'
-  gem 'pygments.rb', '~> 1.1.2'
-  gem 'rdiscount', '~> 2.0'
-  gem 'RedCloth', '~> 4.2'
-  gem 'haml', '~> 4.0'
   gem 'compass', '~> 0.12'
   gem 'sass-globbing', '~> 1.0'
-  gem 'rubypants', '~> 0.2'
-  gem 'rb-fsevent', '~> 0.9'
   gem 'stringex', '~> 1.4'
-  gem 'execjs'
-  gem 'therubyracer', :platforms => :ruby
-  gem 'coderay'
   gem 'pry'
 end
 
@@ -24,7 +15,6 @@ group :jekyll_plugins do
   gem 'jekyll-sitemap'
   gem 'jekyll-time-to-read'
   gem 'octopress', '~> 3.0'
-  gem 'octopress-filters'
   gem 'octopress-include-tag'
 end