Mike Howard on "Redirect once plugin update completed"

What is the best way to redirect users to a page once my plugin has updated?

Updates are performed within WordPress itself, so I thought that adding a version number into the options table and doing a camparison would be best.

I did this and hooked into it using admin_init but it did not work.

My function was...

function has_updated(){
wp_redirect( admin_url( 'path/myupdatepage.php' ) );
exit;
}
add_action(  'admin_init', 'has_updated'  );

but the redirect is not happening