Minor Description
The script dev/run-tests, which is intended for verifying the correctness of pull requests, runs Apache RAT to check for missing Apache license headers. Later, the script does a full compile/package/test sequence.
The script as currently written works fine the first time. But the second time it runs, the Apache RAT checks fail due to the presence of the directory spark-warehouse, which the script indirectly creates during its regression test run.
