Changes

• actix-web 1.0.0 compatibility

• Upgraded logic that evaluates session state, including new SessionStatus field, and introduced session.renew() and session.purge() functionality. Use renew() to cycle the session key at successful login. renew() keeps a session's state while replacing the old cookie and session key with new ones. Use purge() at logout to invalidate the session cookie and remove the session's redis cache entry.