タグ “廃止” 追加 (#378) (#379)

Reviewed-on: http://git.miteruzo.com/miteruzo/btrc-hub/pulls/379
Co-authored-by: miteruzo <miteruzo@naver.com>
Co-committed-by: miteruzo <miteruzo@naver.com>

backend/app/representations/post_repr.rb

@@ -53,7 +53,7 @@ module PostRepr
   end
 
   def tag_json tags
-    tags.map { |tag| TagRepr.inline(tag) }
+    tags.reject(&:deprecated?).map { |tag| TagRepr.inline(tag) }
   end
 
   def thumbnail_url post