User login/session in nickel-jwt-session

I've done some searching for a way to handle user sessions in As I didn't find anything, i created nickel-jwt-session.

This accomplishes a cookie-based user session that is validated on each request. The username is stored in the token which is signed with a secret key. So the user sessions are not stored in memory on the server or in any kind of backing store.

The heavy lifting is done by the jwt crate, and of course nickel itself.

Suggestions and hints are very welcome, including both technical details about my implementation and references to other existing crates.