0.2.0: Gift Inputs. Updated Deps. Bug fix.

• Added support for is_gift and has_gift_message to the order input
  object.
• Jackson now uses the constructors to deserialize to the response model
  classes rather than overriding the access modifiers on them.
• A null pointer bug was fixed in getInput() of the Warning model when
  the input array is not present in the JSON object.
• Update GeoIP2 and other dependencies.