specifies the name of a CSS class that will be applied to items of the Y-Axis
| key | string | the section's id | 
| label | string | the section's label | 
| section | object | the section object that contains the 'key' and 'label' properties | 
Available only in PRO Edition
scheduler.templates.timeline_scaley_class = function(key, label,  section){ 
    return "";
};
The template requires the timeline plugin to be activated.