Slight change in documentation's example

[kristos80]

Hi Mika and thanks for the great software,

It's not an issue per se, but if you'd like, update the documentation for the custom Authenticator, so that the __invoke method is declared with a return type.

class RandomAuthenticator implements AuthenticatorInterface {
    public function __invoke(array $arguments) : bool {
        return (bool)rand(0,1);
    }
}

Cheers!

[tuupola]

Good catch, thanks!