Update mopidy & plugins to latest version

[SkeLLLa]

Hello. Mopidy plugins and mopidy itself are outdated. Some of them haven't updated since 2015 and new versions are available. It would be great if you update them. Thanks.

[quimbydogg]

I found that mopidy-spotify 3.0.0 does not allow for searching due to some changes related to oauth. This means the current client in the overlay can only be used for existing playlists and not finding any new music:
mopidy/mopidy-spotify#142

Updating to 3.1.0 (June 2017) solves this. I'm really new to ebuilding but just changed the SRC_URI to point to the latest tar.gz release for a quick local fix.

[mrueg]

Dropped it, won't maintain this overlay actively anymore.