Add support for SendGrid as Email notification handler

src/main/java/io/kamax/mxisd/threepid/notification/phone/PhoneNotificationHandler.java

@@ -40,6 +40,11 @@ public class PhoneNotificationHandler extends GenericNotificationHandler<IPhoneC
         process(connectors, generators);
     }
 
+    @Override
+    public String getId() {
+        return "raw";
+    }
+
     @Override
     public String getMedium() {
         return ThreePidMedium.PhoneNumber.getId();