UTCのexpires_atをappのタイムゾーンに変換する

https://github.com/shikorism/tissue/pull/30#issuecomment-455174326

app/MetadataResolver/KomifloResolver.php

@@ -24,7 +24,7 @@ class KomifloResolver implements Resolver
                 ' - ' .
                 ($json['content']['parents'][0]['data']['title'] ?? '?');
             $metadata->image = $json['content']['cdn_public'] . "/564_mobile_large_3x/" . $json['content']['named_imgs']['cover']['filename'] . $json['content']['signature'];
-            $metadata->expires_at = Carbon::parse($json['content']['signature_expires']);
+            $metadata->expires_at = Carbon::parse($json['content']['signature_expires'])->setTimezone(config('app.timezone'));
 
             return $metadata;
         } else {