So, it looks like you ran the composer command from the correct directory (assuming that Magento is installed in the public/ folder that you changed to) 
The rest of the output is totally not what I would have ever expected to see. The line below makes me question that Magento was installed successfully, but I’m not really sure.
Could not scan for classes inside "/kunder/wpspku_3014/magent_5137/public/vendor/phpunit/phpunit/src/" which does not appear to be a file nor a folder
Then this line was interesting, as it seems to indicate that you ran out of disk space on your server so some files were unable to unzip.
failed to open stream: Disk quota exceeded
It probably wasn’t the best idea to confirm ‘yes’ at all the prompts, as it seems like you’ve gone down the rabbit hole here.
We could work out how to fix this but it would be much quicker to load a recent backup and start over.