SSAS Tabular: perspective descriptions

[furmangg]

http://byobi.com/2016/04/adding-descriptions-for-perspectives-in-tabular/

In 1200 models the following seems to work and the perspective dialog doesn't seem to blow it away upon an edit:

"perspectives": [
  {
    "name": "New Perspective 2",
    "description": "my perspective desc",
    "tables": [