feat: persist user creation date (resolve #31)

migrations/sqlite3/3_user_creation_date.sql

@@ -0,0 +1,20 @@
+-- +migrate Up
+-- SQL in section 'Up' is executed when this migration is applied
+
+-- SQLite does not allow altering a table to add a new column with default of CURRENT_TIMESTAMP
+-- See https://www.sqlite.org/lang_altertable.html
+
+alter table users
+    add `created_at` timestamp default '2020-01-01T00:00:00.000' not null;
+
+alter table users
+    add `last_logged_in_at` timestamp default '2020-01-01T00:00:00.000' not null;
+
+-- +migrate Down
+-- SQL section 'Down' is executed when this migration is rolled back
+
+alter table users
+    drop column `created_at`;
+
+alter table users
+    drop column `last_logged_in_at`;