1.4.0

• Added support for custom inputs. These can be set up from your account portal.
• Added support for the /device/session_age and /device/session_id inputs.
  Use the sessionAge and sessionId constructor parameters on
  MaxMind.MinFraud.Request.Device to set them.
• Added support for the /email/first_seen output. Use FirstSeen on
  MaxMind.MinFraud.Response.FirstSeen to access it.
• Added the following new values to the PaymentProcessor enum:
  • AmericanExpressPaymentGateway
  • Bluesnap
  • Commdoo
  • Curopayments
  • Ebs
  • Exact
  • Hipay
  • LemonWay.
  • Oceanpayment
  • Paymentwall
  • Payza
  • Securetrading
  • SolidtrustPay
  • Vantiv
  • Vericheck
  • Vpos
• Updated the docs for MaxMind.MinFraud.Response.Address now that
  IsPostalInCity may be returned for addresses world-wide.
• Switched to the updated MSBuild .NET Core build system.
• Moved tests from NUnit to xUnit.net.