refactor!: drop backup/restore for now

This will be done with the bot from now on.

cli/app/app.go

@@ -12,8 +12,8 @@ var AppCommand = cli.Command{
 	ArgsUsage: "<app>",
 	Description: `
 This command provides all the functionality you need to manage the life cycle
-of your apps. From initial deployment, day-2 operations (e.g. backup/restore)
-to scaling apps up and spinning them down.
+of your apps. From initial deployment to day-2 operations to scaling apps up
+and spinning them down.
 `,
 	Subcommands: []cli.Command{
 		appNewCommand,
@@ -22,8 +22,6 @@ to scaling apps up and spinning them down.
 		appDeployCommand,
 		appUpgradeCommand,
 		appUndeployCommand,
-		appBackupCommand,
-		appRestoreCommand,
 		appRemoveCommand,
 		appCheckCommand,
 		appListCommand,