If you hate heroku, you have your own server...
If not, 
cp env.example .env
# add values to .env file
# edit path to fit your need in slackin.sh file
vi slackin.sh
# add init.d script for slackin
sudo -i
cd /vagrant
cp slackin.sh /etc/init.d/slackin
chmod a+x /etc/init.d/slackin
update-rc.d slackin defaults
service slackin start
# edit server name in nginx-slackin.conf
ln -s /vagrant/nginx-slackin.conf /etc/nginx/sites-enabled/nginx-slackin.conf
service nginx reload
Voilà!