[feature/api] Removed unnecessary function

The verify function in the auth repository was pretty much useless
after the auth function was implemented. From now on the verify route
uses the auth function instead.

Updated the development API client by implementing running requests
as guest.

PHPBB3-11595
[feature/api] Added tests for the api auth class

Added unit and functional tests for the auth class of the api.

PHPBB3-11595