updateMigration method
Implementation
Future<Migration> updateMigration(Migration migration) async {
List<Migration> migrationsUpdated = await (update(migrations)
..where((tbl) => tbl.name.equals(migration.name)))
.writeReturning(migration);
assert(migrationsUpdated.length == 1);
migration.become(migrationsUpdated.first);
return migration;
}