[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 2392ff0 [libFuzzer] Error and exit if user supplied fuzzer writeable directories don't exist
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   2392ff0..eed0af6  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to eed0af6179ca4fe9e60121e0829ed8d3849b1ce5.
CMake Error at CMakeLists.txt:3 (cmake_minimum_required):
  CMake 3.13.4 or higher is required.  You are running version 3.7.1


-- Configuring incomplete, errors occurred!