Ajax handler for creating new category from Press This.

function wp_ajax_press_this_add_category() {
	_deprecated_function( __FUNCTION__, '4.9.0' );
	if ( is_plugin_active( 'press-this/press-this-plugin.php' ) ) {
		include WP_PLUGIN_DIR . '/press-this/class-wp-press-this-plugin.php';
		$wp_press_this = new WP_Press_This_Plugin();
		$wp_press_this->add_category();
	} else {
		wp_send_json_error( array( 'errorMessage' => __( 'The Press This plugin is required.' ) ) );
	}
}