Add created timestamps for tags

src/database/schema.rs

@@ -11,6 +11,7 @@ table! {
         id -> Integer,
         photo_name -> Text,
         tag_id -> Integer,
+        created_time -> BigInt,
     }
 }
 
@@ -18,6 +19,7 @@ table! {
     tags (id) {
         id -> Integer,
         name -> Text,
+        created_time -> BigInt,
     }
 }