Supply a TestLogger

[abilson]

Integration tests typically stub out the IAPILog interface, which means that app logs are not captured during integration testing. These logs could be vital for two reasons:

1. Helps to diagnose test failures, esp. when in a CI/CD pipeline.

2. Makes integration test logging possible. That is, we could add helpful logs in Test Helpers to further explain what's happening in the final results

My first thought is to send these logs to console, which may work well if the integration tests are executed via the command line. A flat .log file may be a suitable alternative.