Using Command returns 0 on failed upload

[DjThossi]

Hey

First of all, thank you for building this lib. I really like it and the possibilities with it.

I use this library within a symfony project.
I run it on command-line like this,
php bin/console --env=prod backup-manager:backup development dropbox -c gzip --filename "$(date +'%Y%m%d-%H%M%S')-backup.sql"

This command returns 0 indifferent if dropbox upload worked or not.

I figured out that this is the case because of not using the result writeStream method.

I found it in TransferFile.php

    /**
     * @throws FileExistsException
     * @throws FileNotFoundException
     */
    public function execute()
    {
        $this->destinationFilesystem->writeStream(
            $this->destinationPath,
            $this->sourceFilesystem->readStream($this->sourcePath)
        );
    }

Would it be possible, in the close future, to return the failing of writeStream up to the surface?

For it would be indifferent whether the Exception is thrown to the surface or at least the command would fail.

Background: I'd like to use the command together with healthchecks.io and know when the command finished successfully. If the command would fail I could get automatically be notified.

If you have any further question please don't hesitate to ask.