TestRegionRebalancing

[Ted Yu]

Hi,
I have a question about TestRegionRebalancing.assertRegionsAreBalanced()
I see hardcoded slop of 0.1
In 0.90 and beyond, sloppiness is gone.
Therefore:
    // TODO: Fix this test.  Old balancer used to run with 'slop'.  New
    // balancer does not.
I want to get your opinion on how this test should be rewritten.

Thanks