public static update(values: Object, options: Object): Promise>
check documentation once http://docs.sequelizejs.com/class/lib/model.js~Model.html#static-method-update
Project.update(
// Set Attribute values
{ title:'a very different title now' },
// Where clause / criteria
{ _id : 1 }
).then(function(result) {
//it returns an array as [affectedCount, affectedRows]
})