gd_user: Retrieve information about the current Google user
Description
Display information about the Google user that has authorized
googlesheets to call the Drive and Sheets APIs on their behalf.
Returns and prints the user's display name, email, the date-time of info
lookup, and the validity of the current access token. This is a subset of the
information available from
https://developers.google.com/drive/v2/reference/about/get{the "about"
endpoint} of the Drive API.