fixed capitalizations [ci skip]

jQuery, SQLite3 and Unicorn use these respective capitalizations pretty much everywhere else in the comment sections of the project.

guides/code/getting_started/Gemfile

@@ -3,7 +3,7 @@ source 'https://rubygems.org'
 
 # Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
 gem 'rails', '4.1.0'
-# Use sqlite3 as the database for Active Record
+# Use SQLite3 as the database for Active Record
 gem 'sqlite3'
 # Use SCSS for stylesheets
 gem 'sass-rails', '~> 4.0.1'
@@ -14,7 +14,7 @@ gem 'coffee-rails', '~> 4.0.0'
 # See https://github.com/sstephenson/execjs#readme for more supported runtimes
 # gem 'therubyracer',  platforms: :ruby
 
-# Use jquery as the JavaScript library
+# Use jQuery as the JavaScript library
 gem 'jquery-rails'
 # Turbolinks makes following links in your web application faster. Read more: https://github.com/rails/turbolinks
 gem 'turbolinks'
@@ -29,7 +29,7 @@ gem 'spring',        group: :development
 # Use ActiveModel has_secure_password
 # gem 'bcrypt', '~> 3.1.7'
 
-# Use unicorn as the app server
+# Use Unicorn as the app server
 # gem 'unicorn'
 
 # Use Capistrano for deployment