Log Message:
(www/R-googledrive) Updated 2.1.0 to 2.1.1

# googledrive 2.1.1

* `drive_auth(subject =)` is a new argument that can be used with
  `drive_auth(path =)`, i.e. when using a service account. The `path` and
  `subject` arguments are ultimately processed by
  `gargle::credentials_service_account()` and support the use of a service
  account to impersonate a normal user (#413).

* All requests now route through `gargle::request_retry()` (#380).

* `drive_scopes()` is a new function to access scopes relevant to the Drive API.
  When called without arguments, `drive_scopes()` returns a named vector of
  scopes, where the names are the associated short aliases. `drive_scopes()` can
  also be called with a character vector; any element that's recognized as a
  short alias is replaced with the associated full scope (#430).

* Various internal changes to sync up with gargle v1.5.0.