fix release task

prepare v3.1.1 release

Merge #202

202: bump version r=Mic92 a=Mic92



Co-authored-by: Jörg Thalheim <joerg@thalheim.io>

bump version

Better error messages

* exposes failure responses in CommandError exceptions

asyncio fixes

- tolerate early disconnects

Asyncio fixes

Revert typing annotations

Last release contained wip code.

Happy Christmas

* Breaking changes: albumart now returns dictionary :code:`{"size": "...",
"binary": b"..."}` instead of just a string
* add readpicture command
* add partition, newpartition and delpartition commands
* add moveoutput command
* removed deprecated `send_` and `fetch_` commands. Use the asyncio or twisted API instead for asynchronous mpd commands.

Re-add use_unicode

- 2.0.0 also dropped use_unicode parameter with no backwards
  compatibility. This versions just deprecates the parameter.