remove duplicate testname from error msg

remove subtest for test setup loop

do not break on test failure

  https://github.com/kubernetes/kubernetes/pull/63665#discussion_r203571355

remove duplicate test.name in output

  https://github.com/kubernetes/kubernetes/pull/63665#discussion_r203574001
  https://github.com/kubernetes/kubernetes/pull/63665#discussion_r203574012