message: Upgrade opencensus-cpp to pick up Zipkin exporter fix.
  Fixes
diff: @@ -259,10 +259,10 @@ REPOSITORY_LOCATIONS = dict(
  urls = ["https://files.pythonhosted.org/packages/dd/bf/4138e7bfb757de47d1f4b6994648ec67a51efe58fa907c1e11e350cddfca/six-1.12.0.tar.gz"],
  ),
  io_opencensus_cpp = dict(
  - sha256 = "a9ba6027436cfa1264860c6be602da7633d9a1f9abcb8838f2ae6bda8c2c14f6",
  - strip_prefix = "opencensus-cpp-13b1a2f29f541b6b2c4cb8bc3f6fbf3589d44227",
  - # 2019-12-01
  - urls = ["https://github.com/census-instrumentation/opencensus-cpp/archive/13b1a2f29f541b6b2c4cb8bc3f6fbf3589d44227.tar.gz"],
  + sha256 = "193ffb4e13bd7886757fd22b61b7f7a400634412ad8e7e1071e73f57bedd7fc6",
  + strip_prefix = "opencensus-cpp-04ed0211931f12b03c1a76b3907248ca4db7bc90",
  + # 2020-03-24
  + urls = ["https://github.com/census-instrumentation/opencensus-cpp/archive/04ed0211931f12b03c1a76b3907248ca4db7bc90.tar.gz"],
  ),
  com_github_curl = dict(
  sha256 = "01ae0c123dee45b01bbaef94c0bc00ed2aec89cb2ee0fd598e0d302a6b5e0a98",
  