message: Update Closure Rules dependency to HEAD
  This makes the definition consistent with TensorBoard and TensorFlow
  Serving. It's better to track HEAD than the release versions.
diff: @@ -2,11 +2,11 @@ workspace(name = "org_tensorflow")
  http_archive(
  name = "io_bazel_rules_closure",
  - sha256 = "25f5399f18d8bf9ce435f85c6bbf671ec4820bc4396b3022cc5dc4bc66303609",
  - strip_prefix = "rules_closure-0.4.2",
  + sha256 = "110fe68753413777944b473c25eed6368c4a0487cee23a7bac1b13cc49d3e257",
  + strip_prefix = "rules_closure-4af89ef1db659eb41f110df189b67d4cf14073e1",
  urls = [
  - "http://mirror.bazel.build/github.com/bazelbuild/rules_closure/archive/0.4.2.tar.gz", # 2017-08-29
  - "https://github.com/bazelbuild/rules_closure/archive/0.4.2.tar.gz",
  + "http://mirror.bazel.build/github.com/bazelbuild/rules_closure/archive/4af89ef1db659eb41f110df189b67d4cf14073e1.tar.gz",
  + "https://github.com/bazelbuild/rules_closure/archive/4af89ef1db659eb41f110df189b67d4cf14073e1.tar.gz", # 2017-08-28
  ],
  )
  