GNU R access Google sheets using the sheets API V4

 Interact with Google Sheets through the Sheets API v4
 <https://developers.google.com/sheets/api>. "API" is an acronym for
 "application programming interface"; the Sheets API allows users to
 interact with Google Sheets programmatically, instead of via a web
 browser. The "v4" refers to the fact that the Sheets API is currently
 at version 4. This package can read and write both the metadata and
 the cell data in a Sheet.