Update skip_tracker test directory

After the last file restructuring, the tests dir was removed.
Now, all tests are in tempest/

Change-Id: Icffc6d39dadf066f577e0b6b5526abb43e674d86
Unskipped object storage test

The bug #1097137 got expired and I couldn't reproduce it.

Change-Id: Ie78e637691fdce3ae7bb7f0e5570e31efff31166
Merge "Unskipped object storage test"
Merge "Update skip_tracker test directory"