customerio.go
func (c *CustomerIO) TrackAnonymous(eventName string, data map[string]interface{}) error {
	body := map[string]interface{}{"name": eventName, "data": data}
	j, err := json.Marshal(body)

	if err != nil {
		return err
	}

	status, responseBody, err := c.request("POST", c.anonURL(), j)

	if err != nil {
		return err
	} else if status != 200 {
		return &CustomerIOError{status, c.anonURL(), responseBody}
	}

	return nil
}
func (c *CustomerIO) TrackAnonymous(eventName string, data map[string]interface{}) error {
	body := map[string]interface{}{"name": eventName, "data": data}
	j, err := json.Marshal(body)

	if err != nil {
		return err
	}

	status, responseBody, err := c.request("POST", c.anonURL(), j)

	if err != nil {
		return err
	} else if status != 200 {
		return &CustomerIOError{status, c.anonURL(), responseBody}
	}

	return nil
}
// TrackAnonymous sends a single event to Customer.io for the anonymous user