Set-up various type of testing for DataFusion: - [x] [Compare expected and observed plans in CI](https://github.com/apache/datafusion-ray/issues/9) - [ ] [Compare results produced by DataFusion Ray and DataFusion](https://github.com/apache/datafusion-ray/issues/11) - [ ] Run tests on K8s
