Optional. Whether or not to force the user to approve the app again if they’ve already done so. If false (default), a user who has already approved the application may be automatically redirected to the URI specified by redirect_uri. If true, the user will not be automatically redirected and will have to approve the app again.
From https://developer.spotify.com/web-api/authorization-guide/
Make is_token_expired_public on SpotifyClientCredentials and SpotifyOAuth.
This method is useful for checking whether tokens that have been stored in cookies etc have timed out. So it's useful for library users to have access to it.
Refactor common implementation of is_token_expired
