message: Try to switch to clang60 in CI
diff: #!/bin/bash
  # version of clang we want to use
  -CLANG_VERSION=5.0
  +CLANG_VERSION=6.0
  # version of libcxx and libcxxabi we want to use
  -CXX_VERSION=5.0.2
  +CXX_VERSION=6.0.1
  # Steps specific to our CI environment
  -# CI runs on Ubuntu 14.04, we need to install clang-5.0 and th
  +# CI runs on Ubuntu 14.04, we need to install clang-5.0 and the
  # appropriate libc++ ourselves
  if [ "$KOKORO_BUILD_ID" ]; then
  sudo ln -s /usr/include/x86_64-linux-gnu/asm /usr/include/asm
  