code: func (s *TwilioSMSService) Send(phonenumber string, message string) (err error) {
  	client := &http.Client{}
  
  	data := url.Values{
  		"MessagingServiceSid": {s.MessagingServiceSID},
  		"To":   {phonenumber},
  		"Body": {message},
  	}
  
  	req, err := http.NewRequest("POST", "https://api.twilio.com/2010-04-01/Accounts/"+s.AccountSID+"/Messages.json", strings.NewReader(data.Encode()))
  	if err != nil {
  		log.Error("Error creating sms request: ", err)
  		return
  	}
  	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
  	req.SetBasicAuth(s.AccountSID, s.AuthToken)
  	resp, err := client.Do(req)
  	if err != nil {
  		log.Error("Error sending sms via Twilio: ", err)
  		return
  	}
  	defer resp.Body.Close()
  	body, err := ioutil.ReadAll(resp.Body)
  	if resp.StatusCode != http.StatusCreated {
  		log.Error("Problem when sending sms via Twilio: ", resp.StatusCode, "\n", string(body))
  		err = errors.New("Error sending sms")
  	}
  	log.Infof("SMS: sms sent to %s", phonenumber)
  	return
  }
docs: //Send sends an SMS