This was copied from https://medium.com/@timleland/zero-downtime-laravel-forge-deploys-6f1251559996#.m05tuzros

zero-downtime.sh

# stop script on error signal
set -e

# remove old deployment folders
if [ -d "/home/forge/weather-deploy" ]; then
 rm -R /home/forge/weather-deploy
fi
if [ -d "/home/forge/weather-backup" ]; then
 rm -R /home/forge/weather-backup
fi

cp -R /home/forge/weather.timleland.com /home/forge/weather-deploy

# Update
cd /home/forge/weather-deploy
git pull origin master
composer dump-autoload
composer install --no-interaction --prefer-dist --optimize-autoloader
php artisan cache:clear
php artisan route:cache
php artisan view:clear 
php artisan migrate --force
php artisan opcache:clear

# Switch (downtime for microseconds)
mv /home/forge/weather.timleland.com /home/forge/weather-backup
mv /home/forge/weather-deploy /home/forge/weather.timleland.com