Add unit testing for ETL framework

[tomschenkjr]

Admittedly, it's hard to define a solid unit testing framework, but should have some tests to do some regression testing. This should be done in Windows (Appveyor) and Linux (Travis CI) builds.

• Compare outputs of ETL utilities (e.g., Log/A_DatasetLogs, Log/A_ETLRuntimes) to ensure it outputs the "correct" answers
• Ensure four-by-four checks work with ETL utilites
• ...?