* Add proper authorization checks on the new Kobo endpoints.
Important Note: As a side-effect, all CalibreWeb API calls can be
authorized using this token (i.e without a username&password).
- Supports /v1/library/sync call to get list of books
- Supports /v1/library/metadata call to get metadata for a given book
+ Assumes books are stored on Backblaze for metadata call
- Changes to helper.py so that we can return no cover instead of a blank
image.
