fix flaky 3dt test
fix flaky 3dt test

DCOS-9499
https://github.com/dcos/3dt/pull/62

GoelDeepak/dcos,amitaekbote/dcos,mesosphere-mergebot/mergebot-test-dcos,surdy/dcos,mnaboka/dcos,mesosphere-mergebot/mergebot-test-dcos,xinxian0458/dcos,xinxian0458/dcos,darkonie/dcos,mesosphere-mergebot/dcos,asridharan/dcos,dcos/dcos,BenWhitehead/dcos,surdy/dcos,kensipe/dcos,mnaboka/dcos,mellenburg/dcos,asridharan/dcos,GoelDeepak/dcos,vishnu2kmohan/dcos,mnaboka/dcos,amitaekbote/dcos,xinxian0458/dcos,surdy/dcos,dcos/dcos,lingmann/dcos,asridharan/dcos,amitaekbote/dcos,mellenburg/dcos,kensipe/dcos,asridharan/dcos,BenWhitehead/dcos,amitaekbote/dcos,dcos/dcos,branden/dcos,mellenburg/dcos,kensipe/dcos,GoelDeepak/dcos,mesosphere-mergebot/dcos,mesosphere-mergebot/dcos,mesosphere-mergebot/dcos,jeid64/dcos,branden/dcos,darkonie/dcos,lingmann/dcos,BenWhitehead/dcos,jeid64/dcos,GoelDeepak/dcos,darkonie/dcos,mesosphere-mergebot/mergebot-test-dcos,mellenburg/dcos,surdy/dcos,jeid64/dcos,vishnu2kmohan/dcos,darkonie/dcos,kensipe/dcos,mesosphere-mergebot/mergebot-test-dcos,branden/dcos,jeid64/dcos,mnaboka/dcos,dcos/dcos,dcos/dcos,vishnu2kmohan/dcos,vishnu2kmohan/dcos,lingmann/dcos,mnaboka/dcos,branden/dcos,lingmann/dcos,darkonie/dcos,xinxian0458/dcos,BenWhitehead/dcos