:bug: #174 just deleting returns from undefined episodes in list sorts

vue-theme/src/store/modules/arrangements.js

         if(!byEpisode[relatedEpisode]) byEpisode[relatedEpisode] = []
         byEpisode[relatedEpisode].push(post)
     })
+    // TODO: Delete any undefined for now. Should figure out how these get returned in the firstplace.
+    delete byEpisode['undefined']
     const flatPacked = _insertInBetweens(byEpisode)
     return flatPacked
 }