Added TokenStatus enum.
Added .status field to Csrf struct which has the type of TokenStatus
check_if_token_exist() function replaced by check_token_status() function. It returns a variant of TokenStatus, which implements Debug, Clone and PartialEq derive macros.
A bug fixed on protection mechanism. uuid version upgraded to 1.11.0 .
Added expiration mechanism, now you can set when a csrf token will be expire and give an ip to new one. This won't break any of the backward code.
Fixed some documentation typos.
csrf_guard released.