Add 'gem thin': WebBrick is deprecated

Gemfile

@@ -35,6 +35,7 @@ gem 'sdoc', '~> 0.4.0', group: :doc
 
 # Use Capistrano for deployment
 # gem 'capistrano-rails', group: :development
+gem 'thin'
 
 group :development, :test do
   # Call 'byebug' anywhere in the code to stop execution and get a debugger console
@@ -48,4 +49,3 @@ group :development do
   # Spring speeds up development by keeping your application running in the background. Read more: https://github.com/rails/spring
   gem 'spring'
 end
-