v0.8.0

Changes

• change docker base image to adoptopenjdk 11
• retrieve file size of books when scanning. Add file size in REST API and OPDS.

Bug fixes

• Swagger is not showing Kotlin nullable types as optional (fixes #15)
• compare file modification time at millisecond. With JDK 9+ on Windows, time precision of the underlying clock would go over 6 digits, which is the precision of the timestamps in database, which would lead to loss of precision on saved timestamps, and failing comparisons of modification times at every library scan
• return only books in ready state via OPDS, else it would throw an error 500 because metadata is not ready
• prevent circular loop in the error resolver, which would complain in logs