Add deck_id to slidedecks asset

add-deck-asset.py

import json
import models
from google.appengine.ext import ndb

opaqueID = '9f3cccbe-ee94-4bd6-9ba6-96efb1967ae4'

deck_asset = models.DBAsset.all().filter('opaqueID = ', opaqueID).filter('assetType = ', 'slidedecks').get()
asset = json.loads(deck_asset.asset)

# Add new deck_id:
asset["deck_ids"].append("4abd5f17-dd8b-42ec-a5e8-d9fecbeebdf9")

deck_asset.asset = json.dumps(asset)

# Update deck asset:
deck_asset.put()