document release procedures
Update release-howto.rst

reminder to close off the current release on GitHub
Small typo in the GitHub repository URL
Merge pull request #122 from dimlev/patch-1

Small typo in the GitHub repository URL
Adds SoCo.get_sonos_playlists and MLSonosPlaylist
Added ( so far not working ) test_mlsonosplaylist
Fixed specific SONOS_PLAYLIST_XML and SONOS_PLAYLIST_DICT
Removed redundant ( and failing ) local overwrite of item_id
Fixes for uri and title in MLSonosPlaylist test.
Added blank line.
Linting complaints from flake8.