Add README.md to test_util
Add README.md to test_util

mesosphere-mergebot/dcos,mesosphere-mergebot/mergebot-test-dcos,mellenburg/dcos,GoelDeepak/dcos,asridharan/dcos,mesosphere-mergebot/dcos,amitaekbote/dcos,mesosphere-mergebot/dcos,amitaekbote/dcos,dcos/dcos,branden/dcos,mesosphere-mergebot/mergebot-test-dcos,amitaekbote/dcos,surdy/dcos,branden/dcos,dcos/dcos,mellenburg/dcos,kensipe/dcos,BenWhitehead/dcos,lingmann/dcos,surdy/dcos,mellenburg/dcos,amitaekbote/dcos,BenWhitehead/dcos,dcos/dcos,kensipe/dcos,GoelDeepak/dcos,BenWhitehead/dcos,kensipe/dcos,dcos/dcos,GoelDeepak/dcos,surdy/dcos,lingmann/dcos,GoelDeepak/dcos,mesosphere-mergebot/dcos,lingmann/dcos,asridharan/dcos,branden/dcos,surdy/dcos,asridharan/dcos,kensipe/dcos,mellenburg/dcos,mesosphere-mergebot/mergebot-test-dcos,branden/dcos,lingmann/dcos,mesosphere-mergebot/mergebot-test-dcos,asridharan/dcos,dcos/dcos,BenWhitehead/dcos