def create
      request = Request.post_xml('authorizations/request', api_version, credentials, xml)
      response = Response.new(request)
      update_attributes(response.serialize)

      response.success?
    end
def create
      request = Request.post_xml('authorizations/request', api_version, credentials, xml)
      response = Response.new(request)
      update_attributes(response.serialize)

      response.success?
    end
Post and create an Authorization.
 Return Boolean.