Remove double declaration of `void' method in CertoDirect.
Merge pull request #284 from hron/certo-direct-remove-double-void-declaration

CertoDirect: Remove double declaration of #void.
Adding order details to create transaction authorize net method when appropriate
Update contributing link
[Enhancement] Secure Pay AU gateway updated to handle periodic payments. Plus enhancements to unit and remote tests
Authorize.Net SIM support
Fix up requires for Authorize.Net SIM.
Merge pull request #286 from tommeier/securepayau

Secure Pay AU: Handle periodic payments.
Viaklix: Add discover as a supported card type.

Closes #252
Create base class for view type tests, fix dependency issues with tests
Merge pull request #288 from jduff/base_test_class_for_view_tests

Create base class for view type tests, fix dependency issues with tests
Refactor ActionViewHelperTest to a module
[Gateway] Add new NABTransact(AU) Gateway
Merge pull request #289 from tommeier/nabtransact_2

Add NAB Transact (AU) Gateway.
Add support for DoReferenceTransactionRequest to PayPal Express API;
Allow using BAID recieved from DoExpressCheckoutPaymentRequest (after setting up the transaction by passing BillingAgreementDetails into SetExpressCheckoutRequest).
Update docs with latest changes.
Merge pull request #290 from where/paypal-billing-agreement-fresh

PayPal Express: Add Support for Reference Transactions using BAIDs
Authorize.Net CIM: Add support for optional refund fields [nilmethod]
Fix bug in SecurePayTech gateway that causes CVV varification to be ignored
Merge pull request #292 from tlconnor/master

SecurePayTech: Fix EnableCSC parameter so CVV codes are checked.