pip uninstall requests yum reinstall python-requests pip uninstall six yum reinstall python-six pip uninstall urllib3 yum reinstall python-urllib3 ; yum install http://cbs.centos.org/kojifiles/packages/pyOpenSSL/16.2.0/3.el7/noarch/python2-pyOpenSSL-16.2.0-3.el7.noarch.rpm ; yum install certbot certbot-apache