beets 1.3.13

This is a tiny bug-fix release. It copes with a dependency upgrade that broke beets. There are just two fixes:

• Fix compatibility with Jellyfish version 0.5.0.
• embedart: In auto mode (the import hook), the plugin now respects the write config option under import. If this is disabled, album art is no longer embedded on import in order to leave files untouched---in effect, auto is implicitly disabled. #1427