Adding snapshot tests to Build Configs

This week, I've started to add snapshot tests to the Build Configs project.

I had unit tests for the DTO validation to ensure the configuration was correct, but the main thing I wanted to test was I could run it for a given configuration file and get the expected files and contents to be generated.

With snapshot tests, I generate the files for each configuration and compare them to a set that I know to be correct.

If the files match, the tests pass, but, if they don't - such as a bug in the code, the tests will fail.

This is the level that I want to be testing this project and that provides the most value.

If a snapshot test fails, I can try to replicate the underlying issue in a unit test whilst also fixing the snapshot test.