0.7.0-beta1

• .NET Core support.
• Email request class constructor now takes a string email address rather
  than a MailAddress. This was does as CoreFX does not currently have
  System.Net.Mail.
• Exceptions are no longer serializable.
• Added the following new values to the PaymentProcessor enum:
  ConceptPayments, Ecomm365, Orangepay, and PacnetServices.