Version 0.8.4

Changed

• Bumped dependencies versions.
• Install requirements from requiements.txt in Dockerfile.
• Changed target python version to 3.8.

Fixed

• Fixed typo in source_gateway.py that prevented using cookies from browsers
• Fixed integrity error when adding assets. #70
• Fixed issue where text packaging breaks without author name #74.
• Fixed html packaging breaking when sorting volumes #74.