Implement 'Account Updater Batch Request' and 'Account Updater RFR' features

* If LitleOnline::Communications.http_post receives a config hash whose URL does not have a path, default path to / since Net::HTTP#request_post requires a path argument
* Refactor LitleOnline::SchemaValidation.validate_required to validate Arrays along with other Objects
* Add LitleOnline::TestSharedData at test/shared/data.rb to encapsulate data shared across tests
  * Define LitleOnline::TestSharedData.real_certification_hash class method to return a hash containing the real certification server URL
* Refactor rake test:certification to use test/certification/ts_all.rb instead of requiring tests with a wildcard
* Add LitleOnline::LitleRequest and require in lib/LitleOnline.rb
* Add XML classes LitleOnline::Token, LitleOnline::LitleRequest, LitleOnline::BatchRequest, LitleOnline::AccountUpdate, LitleOnline::RFRRequest and LitleOnline::AccountUpdateFileRequestData
  * Include unit tests
  * Use classes for litleRequest batch requests
* Define LitleOnline::LitleRequest#account_updater_batch_request to perform Account Updater Batch requests
  * Add Account Updater Certification Testing
  * Require Account Updater certification tests in test/certification/ts_all.rb
  * Require test_accountUpdater in test/functional/ts_all.rb
  * Add functional tests for Account Updater
  * Add LitleOnline::LitleRequest#account_updater_batch_request unit tests
* Define LitleOnline::LitleRequest#account_updater_request_for_response to perform Account Updater RFR requests
  * Add Account Updater RFR Request functional tests
  * Add LitleOnline::LitleRequest#account_updater_batch_request unit tests
* Add LitleOnline::LitleRequest#num_batch_requests so each method can define litleRequest node numBatchRequests attribute
Merge pull request #1 from LessonPlanet/sw/add-account-updater

Implement 'Account Updater Batch Request' and 'Account Updater RFR' features