Deleting file triggers stale project warning

[catarak]

Nature of issue?

• Found a bug

Details about the bug:

• Web browser and version: Chrome
• Operating System: Mac OSX
• Steps to reproduce this bug:

1. Create a new sketch
2. Save it
3. Create a new file (likea.js or something simple)
4. Save the sketch
5. Delete a.js
6. Save the sketch

The API request will return a 409 error—this is because the DELETE call doesn't return the updated sketch... and it should.