use channel last_modified field to store updated timestamp

more appropriate than to store it in album date

mopidy_somafm/actor.py

@@ -51,14 +51,14 @@ def lookup(self, uri):
         # Build album (idem as playlist, but with more metada)
         album = Album(
             artists=[artist],
-            date=channel_data['updated'],
             images=[channel_data['image']],
             name=channel_data['title'],
             uri='somafm:channel:/%s' % (channel_name))
 
         track = Track(
             artists=[artist],
             album=album,
+            last_modified=channel_data['updated'],
             comment=channel_data['description'],
             genre=channel_data['genre'],
             name=channel_data['title'],

mopidy_somafm/somafm.py

@@ -8,7 +8,6 @@
 import requests
 import urlparse
 import collections
-from datetime import datetime
 
 try:
     import xml.etree.cElementTree as ET
@@ -76,8 +75,7 @@ def refresh(self, encoding, quality):
                 if key in ['title', 'image', 'dj', 'genre', 'description']:
                     channel_data[key] = val
                 elif key == 'updated':
-                    channel_data['updated'] = datetime.fromtimestamp(
-                        int(val)).strftime("%Y-%m-%d")
+                    channel_data['updated'] = int(val)
                 elif 'pls' in key:
                     pls_quality = key[:-3]
                     pls_format = child_detail.attrib['format']