问Rails数据库配置未指定适配器。我做什么好？

EN

/Users/davidzabner/.rvm/gems/ruby-1.9.3-p448/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_specification.rb:47:in `resolve_hash_connection'
    /Users/davidzabner/.rvm/gems/ruby-1.9.3-p448/gems/activerecord-3.2.13/lib/active_record/connection_adapters/abstract/connection_specification.rb:41:in `resolve_string_connection'
    ...
    /Users/davidzabner/.rvm/gems/ruby-1.9.3-p448/gems/railties-3.2.13/lib/rails/application.rb:103:in `require_environment!'
    /Users/davidzabner/.rvm/gems/ruby-1.9.3-p448/gems/railties-3.2.13/lib/rails/application.rb:297:in `block (2 levels) in initialize_tasks'
    /Users/davidzabner/.rvm/gems/ruby-1.9.3-p448/bin/ruby_noexec_wrapper:14:in `eval'
    /Users/davidzabner/.rvm/gems/ruby-1.9.3-p448/bin/ruby_noexec_wrapper:14:in `<main>'

development:
  adapter: sqlite3
  database: db/development.sqlite3
  pool: 5
  timeout: 5000

test:
  adapter: sqlite3
  database: db/test.sqlite3
  pool: 5
  timeout: 5000

production:
  adapter: sqlite3
  database: db/production.sqlite3
  pool: 5
  timeout: 5000

source 'https://rubygems.org'

gem "therubyracer"
gem "less-rails" #Sprockets (what Rails 3.1 uses for its asset pipeline) supports LESS
gem "twitter-bootstrap-rails"
gem 'jquery-rails'
gem 'devise'

gem 'rails', '3.2.13'

# Bundle edge Rails instead:
# gem 'rails', :git => 'git://github.com/rails/rails.git'

group :development, :test do
    gem 'sqlite3'
end

group :production do
    gem 'pg'
end

gem 'mini_magick'
gem "rmagick"
gem "carrierwave"


# Gems used only for assets and not required
# in production environments by default.
group :assets do
  gem 'sass-rails',   '~> 3.2.3'
  gem 'coffee-rails', '~> 3.2.1'

  # See https://github.com/sstephenson/execjs#readme for more supported runtimes
  # gem 'therubyracer', :platforms => :ruby

  gem 'uglifier', '>= 1.0.3'
end

gem 'jquery-rails'

# To use ActiveModel has_secure_password
# gem 'bcrypt-ruby', '~> 3.0.0'

# To use Jbuilder templates for JSON
# gem 'jbuilder'

# Use unicorn as the app server
# gem 'unicorn'

# Deploy with Capistrano
# gem 'capistrano'

# To use debugger
# gem 'debugger'