Fixing list all purchased phone number sample from readme file
@@ -60,7 +60,7 @@ Lists all of your purchased phone numbers
```python
purchased_phone_numbers = phone_numbers_client.list_purchased_phone_numbers()
-purchased_phone_number = purchased_phone_numbers.next()
+for acquired_phone_number in purchased_phone_numbers:
print(acquired_phone_number.phone_number)
```
