Release 0.15.0
- Use Spinach task scheduler instead of Celery: simpler, and eliminates the need for a worker beat node (#2381)
- Fix reps bug involving proxies (#2254, #2237, #1748) (#2395)
- Use Monaco for displaying diffs (fixes #2275, #2260) (#2334)
- Use webpack production mode for building iodide (fixes #2023) (#2402)