we were seeing isort produce different outputs locally and in docker -
this was due to it having different opinions about whether the tests
module (ie all our unit tests) is a first party (local) or third party
(pip installed) import. It's a first party import, so by defining this
in the setup.cfg isort settings, we can force it to be consistent
between environments.
Note: I don't know why it was different in the first place though
also, refactor the org tests into a folder to avoid megalith testing
files.
Also hardcode the org id to a variable so it can be referred to from
various places. In conftest there is now ORGANISATION_ID, which
represents an organisation that `active_user_with_permissions` has
access to
