Get the username from the cookie

AuthUserFromRequestTiny.rs

impl<'a, 'r> FromRequest<'a, 'r> for AuthUser {
    type Error = ApiError;
    fn from_request(request: &'a Request<'r>) -> request::Outcome<AuthUser, Self::Error> {
        request.cookies()
            .get_private("user_id")
            .and_then(|cookie| cookie.value().parse().ok())
            .into_outcome((Status::Unauthorized,ApiError::unauthorized("Unauthorized or no cookie")))
            .map(|user| AuthUser(user))
    }
}