Updates existing specs with new config code

Earlier work on fixing the tests have meant two or three ways to sort
the problem of $config referencing another spec.

This standardises most of the approaches with the #config_from_contents
helper within a temp dir on an example by example basis.
Fixes find_or_set_default_account when unauthorised

Through a chain of usage #account is called during the authorisation
steps which then tries to make API calls when we know the calls will
fail.

Really we should only do this helper call when adding the client the
first time. This is creating extra API traffic and only helps one case.

As an alternative we should guard against making the call if the acces
token has been voided. At the moment that is still hit/miss.