Add created timestamps for tags

migrations/2021-09-02-000740_create_tags/up.sql

@@ -1,11 +1,13 @@
 CREATE TABLE tags (
     id INTEGER PRIMARY KEY NOT NULL,
-    name TEXT NOT NULL
+    name TEXT NOT NULL,
+    created_time BIGINT NOT NULL
 );
 
 CREATE TABLE tagged_photo (
     id INTEGER PRIMARY KEY NOT NULL,
     photo_name TEXT NOT NULL,
     tag_id INTEGER NOT NULL,
+    created_time BIGINT NOT NULL,
     CONSTRAINT tagid FOREIGN KEY (tag_id) REFERENCES tags (id) ON DELETE CASCADE ON UPDATE CASCADE
 );