[Buildbot] #3445: add test configuration that runs random subset of tests in random order

[Buildbot trac]

#3445: add test configuration that runs random subset of tests in random order
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Reporter:  rutsky     |      Owner:
    Type:  undecided  |     Status:  new
Priority:  major      |  Milestone:  0.9.+
 Version:  master     |   Keywords:
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 When all tests are run sequentially some subtle issues can be missed, e.g.
 https://github.com/buildbot/buildbot/pull/1978

 Additional metabbocfg/Travis configuration should be added that will run
 random subset of tests in random order.

 Dustin says, that `trial` has support such tests run mode.
 Also Dustin mentioned, that it would be nice to have control over random
 seed, so that these tests would be reproducible.

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Ticket URL: <http://trac.buildbot.net/ticket/3445>
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Buildbot: build/test automation