define UCT testing

[Mark Esler]

UCT has many scripts but not a unified testing infrastructure. Many scripts are deprecated and no longer function.

UCT should have a unified test structure which can be ran periodically to verify script changes. Potentially, editing a specific script could cause a git hook to trigger a specific set of test scripts.

Standard testing methods, such as using pytest, should be defined and documented.

$UCT/tests/ centrals test data, but there are also scripts in $UCT/scripts/test_*