1. Copy 'app' and 'pub' folders to the root of the Magento 2 project.
2. Install magento module. 
        bin/magento setup:upgrade
3. Because maintenance module works in 'pub' folder, 
   we need to ensure that file persmissions are properly set,
   accordingly to Magento 2 documentation. For Ubuntu that might be:
        chown -R :www-data pub/errors/creatuity_maintenance/
        find pub/errors/creatuity_maintenance/ -type d -exec chmod 770 {} \; 
        find pub/errors/creatuity_maintenance/ -type f -exec chmod 660 {} \;
4. Flush caches. Example:
        bin/magento cache:flush
        rm -rf var/generation


