add logging for sms sending

smash/web/nexmo_gateway.py

+import logging
+
 import nexmo
 from django.conf import settings
 
+logger = logging.getLogger(__name__)
+
 
 class Nexmo:
     """
@@ -28,4 +32,5 @@ class Nexmo:
     def send_sms(self, device, token):
         body = 'Your authentication token is %s' % token
         phone_number = device.number.as_e164
+        logger.info("Sending authentication token to %s", phone_number)
         self.client.send_message({'to': phone_number, 'from': self.default_from, 'text': body})