Prevent GceToken$new() from initiating a legacy httr token cache #221
Description
On GCE, I see this:
> library(googledrive) > drive_find(n_max = 5)
Use a local file ('.httr-oauth'), to cache OAuth access credentials between R sessions?
1: Yes
2: No
--
Selection:
because GceToken doesn't implement $initialize() and delegates to Token2.0 which eventually calls httr:::use_cache().
One way to suppress it is to simply set the option httr_oauth_cache = FALSE. That's probably the simplest fix, i.e. to do that locally in credentials_gce().