def update email, card_or_token = nil
      attributes = self.class.attributes - [:token, :created_at]
      options    = self.class.parse_options_for_request(attributes, email: email, card: card_or_token)
      response   = self.class.put(URI.parse(PinPayment.api_url).tap{|uri| uri.path = "/1/customers/#{token}" }, options)
      self.email = response['email']
      self.card  = response['card']
      self
    end
def update email, card_or_token = nil
      attributes = self.class.attributes - [:token, :created_at]
      options    = self.class.parse_options_for_request(attributes, email: email, card: card_or_token)
      response   = self.class.put(URI.parse(PinPayment.api_url).tap{|uri| uri.path = "/1/customers/#{token}" }, options)
      self.email = response['email']
      self.card  = response['card']
      self
    end
Update a customer using the pin API.

 @param [String] email the customer's new email address
 @param [String, PinPayment::Card, Hash] card_or_token the customer's new credit card details
 @return [PinPayment::Customer]