Major Description
When trying to address build test failure in SPARK-20661 we discovered some tables are unexpectedly left behind causing R tests to fail. While we changed the R tests to be more resilient, we investigated further to see what was creating those tables.
It turns out pyspark doctest is calling saveAsTable without ever dropping them. Since we have separate python tests for bucketed table, and we don't check for result in doctest, there is really no need to run the doctest
