Skip test that is reported as unreliable
    
    > Unreliable test timings! On an initial run, this test took 352.68ms,
    > which exceeded the deadline of 200.00ms, but on a subsequent run it
    > took 5.00 ms, which did not. If you expect this sort of variability in
    > your test timings, consider turning deadlines off for this test by
    > setting deadline=None.