* Use transaction for entire migration batch + locking if all migrations are transactional.
* Fix tests.
Use knex instead of query builder.
Do no use single transaction if `disableTransactions` is true.
* Added tests for parallel migrations.
Subtract already done migrations after getting the lock, when there is a wrapping transaction.
* Fix indentation.
* Fix linting errors (which are locally warnings, for some reason).
* Remove `const` keyword.
Remove obsolete `it` clauses.
* No maria. PG first.
* Test only pg and oracle.
* Remove error swallowing.
* Test parallel migration only in postgres (select for update works differently in other databases).
* Add transaction to missed places.
* Remove ignored table name argument.
* Enabled parallel migrations test for `mssql` dialect (still not part of CI test).
Fixed indentation.
