Repository anlegen und Permissons #

mkdir -p  /home/lukas/repos/GoWiki/ 
svnadmin create  /home/lukas/repos/GoWiki/

chown -R www-data:www-data  /home/lukas/repos/GoWiki/ 
chmod -R 775  /home/lukas/repos/GoWiki/ 

You also need to set the required permissions on newly created directories.