message: fix(objectloader): check for nulls and continue
  null type is an object, so nulls here were throwing:
  `"TypeError: Cannot read property 'referencedId' of null"
  `
  checking and continuing when nulls are encountered instead
diff: @@ -143,7 +143,7 @@ export default class ObjectLoader {
  // 2) Iterate through obj
  for( let prop in obj ) {
  - if( typeof obj[prop] !== 'object' ) continue // leave alone primitive props
  + if( typeof obj[prop] !== 'object' || obj[prop] === null ) continue // leave alone primitive props
  if( obj[prop].referencedId ) {
  obj[prop] = await this.getObject( obj[prop].referencedId )
  