Integration tests

[Mecharyry]

Problem

We have unit tests for all our classes, which is great 😄 but it would be good to have some integration tests to make sure complete flows work as we want.

Potential Solution

We need to identify system boundaries and provide alternative implementations e.g. HttpRequestMaker could return exactly the status I want and we can ensure that the rest of the flow works as expected.

Impact

Double check that whole flows work rather than relying on small scoped unit tests.