The clients never get passed useful values to their `__init__` methods.
Rather the real values are passed through later using the `init_app`
method.
So it should be an error if the client is relying on the values that
get passed to it’s init method. Easiest way to ensure this is by making
the `__init__` method not expect any arguments and passing fake values
to the `Super` call.
Mutating dictionaries is gross and doesn’t work as you’d expect. Better
to have the function return a new dictionary instead.
Means we can be explicit that `created_by` is one of the allowed params
when updating a service.
This commit only deals with acceptance by
users who are already in system.
Changed invite client to return invited user objects
instead of dictionaries.
Added commented out test. fixed up fixtures to return invited user
object for invites
