Cleaning up after our tests

When we run our tests, it'll index user documents into our local development database. Over many runs, our database will be filled with a large number of test user documents. Ideally, we want all our tests to be self-contained. This means with each test run, we should reset the state of the database back to the state before the test was run. To achieve this, we must make two further changes to our test code:

• Delete the test user after we have made the necessary assertions
• Run the tests on a test database; in the case of Elasticsearch, we can simply use a different index for our tests