1.0.0

• First production release.
• Connections will now be reused between requests made with the same
  WebServiceClient object.
• WebServiceClient now implements Closeable.
• You are now able to set a proxy to use via the WebServiceClient.Builder
proxy(Proxy) method.
• Updated dependencies.
• Added the following new values to the Payment.Processor enum:
  CONCEPT_PAYMENTS, ECOMM365, ORANGEPAY, and PACNET_SERVICES.