Do not include 0 date albums for spotify searching

[GregorySchwartz]

This commit solves issue #72 by not including spotify albums with a year of 0. This commit will obviously not include any of year 0, but the assumption is spotify (in my experience) will not have 0 years.

[marcaddeo]

@GregorySchwartz so this basically just ignores the 0-year albums completely from the index? That doesn't seem like the correct fix.

For instance, Dub FX's album A Crossworlds has a year of 0 according to mopidy, but a year of 2014 according to the Spotify UI... So there seems to be some sort of disconnect on the "import"?

Disclaimer: I haven't gone in and learned how this thing works yet 😄

[GregorySchwartz]

@marcaddeo that's correct, this is just a stop gap until the real problem is fixed. Obviously we would want all albums that are indexed to be included, regardless of date, but this commit is intended to be a temporary workaround until the real issue is fixed.

[jodal]

60848b6 fixes #72 by ignoring 0-dates in the translator, instead of the user of the translated data, like this PR does.