if to() method is used to set the recipient phonenumber, then it has highest priority (#18)

* if to() method is used to set the recipient phonenumber, then it has the highest priority

* wip

Author: ossycodes

README.md

@@ -144,12 +144,12 @@ It's important to know the Order in which the recipient phone number the notific
 
 2) if you did not define routeNotificationForAfricasTalking() method on the Notifiable class (User.php in this case), then the phone_number attribute of the User will be used ($user->phone_number)
 
-3) Lastly if 1 and 2 are not set, then you can set the recipient phone number using ->to(19283281921)
+3) Lastly if the recipient phone number is set using ->to(1111111), this will overide the phone number provided in either 1 or 2.
 
 ``` php
         return (new AfricasTalkingMessage())
                     ->content('Your SMS message content')
-                    ->to("put the recipient phonenumber here");
+                    ->to("put the recipient phonenumber here"); //eg ->to(11111111)
 ```
 
 ## Testing

src/AfricasTalkingChannel.php

@@ -31,7 +31,11 @@ public function send($notifiable, Notification $notification)
         $message = $notification->toAfricasTalking($notifiable);
 
         if (!$phoneNumber = $notifiable->routeNotificationFor('africasTalking')) {
-            $phoneNumber = $notifiable->phone_number ?? $message->getTo();
+            $phoneNumber = $notifiable->phone_number;
+        }
+
+        if(!empty($message->getTo())) {
+            $phoneNumber = $message->getTo();
         }
 
         if(empty($phoneNumber)) {