We have some purposely brittle ring tests that test rebalances that are
PY2 only. This was because the random seeding between PY2 and PY3 is
different. Now that we're stepping towards py3 only, these tests needed
to be migrated so we don't loose important test coverage.
This patch flips these PY2 only tests to be PY3 only, for the same
reason as before. It took quite a bit of effort to find seeds that would
behave like the ones in the PY2 birttle test.. but found them.
Change-Id: I0978041830ed3e231476719efed66bf9b337ff8a
fce7ad5f18