Uninstall gevent
Closes
-r base.txt
-gevent==1.2.2
gunicorn==19.8.1 # https://github.com/benoitc/gunicorn
psycopg2==2.7.4 --no-binary psycopg2 # https://github.com/psycopg/psycopg2
{%- if cookiecutter.use_whitenoise == 'n' %}
