Gunicorn
From charlesreid1
Learned about when setting up Graphite-API service
http://graphite-api.readthedocs.org/en/latest/api.html
Found this instruction on nginx, gunicorn, and running flask applications with them:
http://www.onurguzel.com/how-to-run-flask-applications-with-nginx-using-gunicorn/
pip install gunicorn sudo apt-get install nginx