Deprecated features

Hi,

On activating version 1.6.1 I get the following errors:

Notice: The called constructor method for WP_Widget is deprecated since version 4.3.0! Use __construct() instead. in /var/www/wp-includes/functions.php on line 3624

Notice: has_cap was called with an argument that is deprecated since version 2.0! Usage of user levels by plugins and themes is deprecated. Use roles and capabilities instead. in /var/www/wp-includes/functions.php on line 3737

https://wordpress.org/plugins/wp-word-count/