coinbase.go
func checkApiErrors(resp response, method string) error {
	if resp.Success == false { // Return errors received from API here
		err := " in " + method + "()"
		if resp.Errors != nil {
			err = strings.Join(resp.Errors, ",") + err
			return errors.New(err)
		}
		if resp.Error != "" { // Return errors received from API here
			err = resp.Error + err
			return errors.New(err)
		}
	}
	return nil
}
func checkApiErrors(resp response, method string) error {
	if resp.Success == false { // Return errors received from API here
		err := " in " + method + "()"
		if resp.Errors != nil {
			err = strings.Join(resp.Errors, ",") + err
			return errors.New(err)
		}
		if resp.Error != "" { // Return errors received from API here
			err = resp.Error + err
			return errors.New(err)
		}
	}
	return nil
}
// checkApiErrors checks for errors returned by coinbase API JSON response
// i.e { "success": false, "errors": ["Button with code code123456 does not exist"], ...}