Moving from slow to active_record helper

Before:

```shell
$ rspec spec/features/instantiate_work_from_persisted_work_type_spec.rb
...

Finished in 0.20914 seconds (files took 2.69 seconds to load)
```

After:

```shell
$ rspec spec/features/instantiate_work_from_persisted_work_type_spec.rb
...

Finished in 0.09997 seconds (files took 0.60017 seconds to load)
```