Expose date information in album

package.json

@@ -1,6 +1,6 @@
 {
   "name": "publikator",
-  "version": "0.16.0",
+  "version": "0.17.0",
   "main": "index.js",
   "repository": "https://github.com/aengl/publikator.git",
   "author": "Lynn Smeria <ae@cephea.de>",

src/generate.js

@@ -28,6 +28,7 @@ const getAlbumInfo = (root, tracks) => ({
   bitrate: collect(tracks, t => t.format.bitrate),
   trackCount: tracks.length,
   cover: tracks[0].cover || null,
+  date: tracks[0].common.date || null,
   tracks: _.sortBy(tracks, 'common.track.no'),
 });