Apache change DocumentRoot
Every time i forget what has to be done to stop with the "Forbidden" page after i change the Root directory. So first add the user you use to add/update/delete your files to www-data group.
usermod -a -G www-data mraiur
Update permissions of file that must be writable by www-data and the user
chmod 0775 FILE
Then in the 000-default in /etc/apache2/sites-available put :
DocumentRoot /NEW_PATH
<Directory "/NEW_PATH">
Options Indexes FollowSymLinks
AllowOverride None
Require all granted
Order allow,deny
Allow from all
</Directory>