Add Google Drive support using rclone cli tool

[islander]

Hello, I've implemented Google Drive support using rclone util.
You may also use it for other many types of storage.

[Ardakilic]

Hey there, Awesome! Thanks for this PR 🎉

I have one single request though, can you please change

-rcr|--rclone-remote)
    RCLONE_REMOTE="$2"
    shift # past argument
    ;;

To something like gdrv and gdrive-remote? So we can use rclone for other implementations in the future

[islander]

Thanks! Ok, I've renamed them.

[Ardakilic]

Awesome, thanks again 🎉