Avoid creating test files in the project directly

[cugni]

What went wrong?

As described in the comment of #402, some tests create files in the project directory, which is not ideal because:

1. It makes the directory messier,
2. There is a higher chance that one commits these files by mistakes
3. The tests can be indeterministic, as the results may vary if these files exist.

To avoid this, we should delete the method withSparkAndTmpDir and replace it with withSparkAndTmpWarehouse.