Change JSON returned by GET /all and /user/:username/:collectionname to also return collection_id

Changes on line 172, 245.

@danielstreit , @jabbrass please re-deploy on azure.

I have added one additional Postman endpoints so you can update an existing collection.
The endpoint is /collection/:collectionID (hence this  pull request).

New Postman Collection Link: https://www.getpostman.com/collections/caa3275e726d13bdccff
I have updated the POSTMAN wiki as well.