A character vector of scopes to request. Pick from those listed
in OAuth 2.0 Scopes for Google APIs.
For certain token flows, the
"https://www.googleapis.com/auth/userinfo.email"
scope is unconditionally
included. This grants permission to retrieve the email address associated
with a token; gargle uses this to index cached OAuth tokens. This grants no
permission to view or send email. It is considered a low value scope and
does not appear on the consent screen.