Move all old db patch files to db/old_migrations/

db/old_migrations/patch-maintenance-cron.sql

@@ -0,0 +1,11 @@
+-- You should not modify if this have pushed to Github, unless it does serious wrong with the db.
+BEGIN TRANSACTION;
+
+DROP TABLE maintenance_timeslot;
+
+-- 999 characters. https://stackoverflow.com/questions/46134830/maximum-length-for-cron-job
+ALTER TABLE maintenance ADD cron TEXT;
+ALTER TABLE maintenance ADD timezone VARCHAR(255);
+ALTER TABLE maintenance ADD duration INTEGER;
+
+COMMIT;