Update stats views.

def update_views(self):
        """Update stats views."""
        # Call the father's method
        super(Plugin, self).update_views()

        # Add specifics informations
        # Alert and log
        self.views['used']['decoration'] = self.get_alert_log(self.stats['used'], maximum=self.stats['total'])
        # Optional
        for key in ['active', 'inactive', 'buffers', 'cached']:
            if key in self.stats:
                self.views[key]['optional'] = True