title: ActiveRecord::AdapterNotSpecified database configuration does not specify adapter
body: <p>When I use heroku open my web app works fine but when I'm using rails s (localhost) I am running into this error:</p>
  
  <pre><code>ActiveRecord::AdapterNotSpecified database configuration does not specify adapter
  </code></pre>
  
  <p>Why is this? </p>
  
  <p>This is my database.yml</p>
  
  <pre><code># PostgreSQL. Versions 8.2 and up are supported.
  #
  # Install the pg driver:
  #   gem install pg
  # On OS X with Homebrew:
  #   gem install pg -- --with-pg-config=/usr/local/bin/pg_config
  # On OS X with MacPorts:
  #   gem install pg -- --with-pg-config=/opt/local/lib/postgresql84/bin/pg_config
  # On Windows:
  #   gem install pg
  #       Choose the win32 build.
  #       Install PostgreSQL and put its /bin directory on your path.
  #
  # Configure Using Gemfile
  # gem 'pg'
  #
  default: &amp;default
    adapter: postgresql
    encoding: unicode
    # For details on connection pooling, see rails configuration guide
    # http://guides.rubyonrails.org/configuring.html#database-pooling
    pool: 5
  </code></pre>
  
  <p>And this is my gemfile:</p>
  
  <pre><code>source 'https://rubygems.org'
  
  
  gem 'pg'
  
  gem 'bootstrap-sass', '~&gt; 3.1.1'
  
  # Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
  gem 'rails', '4.0.3'
  
  # Use SCSS for stylesheets
  gem 'sass-rails', '~&gt; 4.0.0'
  
  # Use Uglifier as compressor for JavaScript assets
  gem 'uglifier', '&gt;= 1.3.0'
  
  # Use CoffeeScript for .js.coffee assets and views
  gem 'coffee-rails', '~&gt; 4.0.0'
  
  # See https://github.com/sstephenson/execjs#readme for more supported runtimes
  # gem 'therubyracer', platforms: :ruby
  
  # 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'
  
  # Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
  gem 'jbuilder', '~&gt; 1.2'
  
  group :doc do
    # bundle exec rake doc:rails generates the API under doc/api.
    gem 'sdoc', require: false
  end
  
  group :production do
    gem 'rails_12factor', '0.0.2'
  end
  
  # Use ActiveModel has_secure_password
  # gem 'bcrypt-ruby', '~&gt; 3.1.2'
  
  # Use unicorn as the app server
  # gem 'unicorn'
  
  # Use Capistrano for deployment
  # gem 'capistrano', group: :development
  
  # Use debugger
  # gem 'debugger', group: [:development, :test]
  </code></pre>