Put googledrive into a de-authorized state. Instead of sending a token,
googledrive will send an API key. This can be used to access public
resources for which no Google sign-in is required. This is handy for using
googledrive in a non-interactive setting to make requests that do not
require a token. It will prevent the attempt to obtain a token
interactively in the browser. The user can configure their own API key
via drive_auth_configure() and retrieve that key via
drive_api_key().
In the absence of a user-configured key, a built-in default key is used.