Simplified GET test to not use POST request.

We want to test the `GET` reqeust in isolation, so it is better to not make the test use the `POST` request in order to add data to the database. We can do that directly in the test.

Consider what would happen if the `POST` request breaks. Then the `GET` tests will probably break as well. It will be harder to determine that its the `POST` request is broken since multiple tests will be failing.