New port: net/grive2 Open source client for Google Drive

Grive2 is the fork of original "Grive" Google Drive client with the
support for the new Drive REST API and partial sync.

WWW: https://github.com/vitalif/grive2/

Submitted by: me
Reviewed by: amdmi3, feld (mentors)
Approved by: amdmi3, feld (mentors)
Differential Revision: D7675