Add recordio encoder/decoder to test_util.
Add recordio encoder/decoder to test_util.

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