$ virtualenv --no-site-packages venv
$ . venv/bin/activate
$ pip install -r requirements.txt
$ ssh sg03
$ cd /www/sgviewer/
$ sudo git pull --ff-only
# To load the server processes:
$ sudo kill -HUP $(cat gunicorn.pid)
# To completely restart the server (this doesn't bring down gunicorn
# nicely; find out why):
$ sudo supervisorctl restart sgviewer