Helios with Role-based Access Control and Separation of Duty

[John Ultra]

Good day everyone,

Allow me to share with you an extended version of Helios that supports both Role-based Access Control (RBAC) and Separation of Duty for the administrative tasks of a Helios election. 

https://github.com/jultra/helios-server/tree/helios-rbac

Let me know what you think. 

PS: Thank you Ben for the really great work!

Best,

John U