destroyData
    destroyData(instanceData)
  
  Deletes instance data given the serialized form of the data and
the url settings.
If url.destroyData is a function, that function will be called.  If url.destroyData is a
string, a request to that string will be made. If url is a string, a DELETE request is made to
url+"/"+IDPROP.
Parameters
- instanceData 
{Object}:The serialized data of the instance.
 
Returns
 {Promise<Object>}: 
A promise that resolves to the deleted instance data.