updateData
Updates a record in the collection.
    function(instanceData)
  
  Updates a record given the serialized form of the data. Returns a promise that resolves to a object that contains the new properties and values of the record.
An example request and response might look like:
connection.updateData({
    id: 5,
    name: "do dishes",
    createdAt: 1477104548997
}).then(function(instanceData){
    instanceData //-> {
    //  id: 5,
    //  name: "do dishes",
    //  createdAt: 1477104540000,
    //  updatedAt: 1477104580000
    //}
})
The following shows how constructor calls updateData
and what it does with the response:
// get its raw data
var instanceData = connection.serializeInstance(myInstance);
connection.updateData(instanceData).then(function(updatedInstanceData){
  connection.updatedInstance(myInstance, updatedInstanceData);
})
  
  Parameters
- instanceData 
{Object}:The serialized data of the instance.
 
Returns
 {Promise<Object>}: 
A promise resolved with the updated data of the newly created instance.
By default, updatedInstance deletes properties in myInstance that are not in updatedInstanceData.  To change that behavior, overwrite updatedInstance.