Type hint on PhoneNumberInstance.carrier should be dict instead of unicode

[sauravc]

The type hint on the carrier property incorrectly marks it as unicode instead of dict here: https://github.com/twilio/twilio-python/blob/6.21.0/twilio/rest/lookups/v1/phone_number.py#L244

Version:
6.21

Code Snippet

>>> p = client.lookups.phone_numbers('+12063211234').fetch(type='carrier')
>>> type(p.carrier)  # Type hint of unicode is incorrect: https://github.com/twilio/twilio-python/blob/6.21.0/twilio/rest/lookups/v1/phone_number.py#L244
<class 'dict'>

Steps to Reproduce

1. Use Twilio Python SDK to do a Lookup API call on a phone number
2. See the type of the carrier property of the resulting PhoneNumberInstance. It is not unicode, but a dict instead.

[childish-sambino]

This issue has been added to our internal backlog to be prioritized. Pull requests and +1s on the issue summary will help it move up the backlog.