[Async]Client.update_credentials(client_id=None, secret=None, key=None) method

It would be very helpful to have a method to update the credentials for a client without having to create a new client. The use case here is a service that contacts the API in a few places in the code base. When the credentials expire, all those clients need to be replaced. If there was an update method, a separate coroutine could monitor a creds file for changes and call the update method and the various parts of the service could wouldn't have to be concerned with replacing the client and closing the old client.

Locate the Python Client entry point and inspect how credentials are initialized and used by existing clients. Implement the requested async update_credentials(client_id=None, secret=None, key=None) behavior so refreshed credentials can be applied without replacing clients or closing the old client. Done means the service use case in the issue works without rebuilding its clients.