Implemented Test Coverage for Auth Reversals

Created Test::Business::CyberSource::AuthorizationReversal
  Implemented attempt_authorization_reversal

In t/02-authorization_reversal.t
  Added Tests for Use Cases for Visa, MasterCard, Discover
    Reverse an Auth
    Reverse an Already Reversed Auth
    Reverse a Capture
    Reverse an Already Captures Auth
    Reverse a Sale
    Reverse a Declined Authorization
  Added test for Amex since Amex Auth's can not be reversed