Confirm authy doesn't use insecure json

[wytcld]

See http://www.infoworld.com/article/3184582/security/critical-flaw-alert-stop-using-json-encryption.html

Your post-install script shows json being used:

add_configuration "$server_conf" "plugin $plugin https://api.authy.com/protected/json $key $pam"

Also, the post-install script or your docs should describe setup that doesn't depend on the post-install script, since some OpenVPN servers will be running multiple daemons on various IPs and ports, whose config files are best edited by hand.