fix multiple-value context and print error in README example
fix multiple-value context and print error in README example

danryan/go-pagerduty,alexpfc/go-pagerduty,alexpfc/go-pagerduty,base2Services/go-pagerduty,danryan/go-pagerduty,alexpfc/go-pagerduty,danryan/go-pagerduty,base2Services/go-pagerduty,base2Services/go-pagerduty