`autodetect': No known ORM was detected

Unable to clean data using database_cleaner.rb; throwing the following issue on running tests.

/Users/prashanth_sams/.rvm/gems/ruby-2.0.0-p598/gems/database_cleaner-1.3.0/lib/database_cleaner/base.rb:147:in `autodetect': No known ORM was detected! Is ActiveRecord, DataMapper, Sequel, MongoMapper, Mongoid, Moped, or CouchPotato, Redis or Ohm loaded? (DatabaseCleaner::NoORMDetected)

spec_helper.rb

ENV["RAILS_ENV"] ||= 'test'

require File.expand_path("../config/environment", __FILE__)
require 'rspec/rails'

Dir[Rails.root.join("spec/support/**/*.rb")].each {|f| require f}

RSpec.configure do |config|

  config.mock_with :rspec

  config.use_transactional_fixtures = false


  config.expect_with :rspec do |expectations|
    expectations.include_chain_clauses_in_custom_matcher_descriptions = true
  end

  config.expect_with :rspec do |c|
    c.syntax = [:should, :expect]
  end

  config.mock_with :rspec do |mocks|
    mocks.verify_partial_doubles = true
  end

  config.color = true

  Selenium::Application.reload_routes!

end

database_cleaner.rb

require 'database_cleaner'

DatabaseCleaner.strategy = :truncation

RSpec.configure do |config|
  config.use_transactional_fixtures = false
  config.before :each do
    DatabaseCleaner.start
  end
  config.after :each do
    DatabaseCleaner.clean
  end
end