Add a script to delete nightly test data that are old.

TEST=tested on tc-build.hot

Change-Id: I6b6bc298b56c6ac79cbbd66f8168bc234580c884
Reviewed-on: https://chrome-internal-review.googlesource.com/150264
Reviewed-by: Yunlian Jiang <yunlian@google.com>
Commit-Queue: Han Shen <shenhan@google.com>
Tested-by: Han Shen <shenhan@google.com>
5 files changed