Update for current JWT lib
Update for current JWT lib

Update to account for changes in the current Firebase JWT library.
You're required to pass an array of allowed decryption algorithms when
calling JWT::decode().

In addition, update the expiration date on the example token to be 2030
so the example will continue to work for a long time. And store the
decrypted JWT in the code so that it's easier to debug. Also, this
provides an example of how to encrypt a JWT.

auth0/php-jwt-example