Remove "update available" message from wordpress dashboard

functions.php

// Remove UPDATE AVAILABLE messages from Wordpress
// Not all clients want to be notifified that their
// site is out of date straight away. This way, they
// are less likely to explore the link themselves
// and either A) Update the site perfectly fine
// or b) mess the whole site up beyond replair (database)

add_action('admin_menu','wphidenag');
function wphidenag() {
  remove_action( 'admin_notices', 'update_nag', 3 );
}