Minor Description
Background: We call TestHiveSparkSession.reset() after each suite that extends TestHiveSingleton. The goal of the function is to reset all Hive-related state before the next suite.
This task: When attempting to make some changes to the Hive-based tests, we noticed some subtle and annoying bugs related to state from one TestHiveSingleton suite affecting the results of later suites. To fix those bugs, and in the interests of making this method more complete, we should fully clean out the Hive warehouse directory in the reset() method.
