[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at ed89eb3 Revert "[FileCheck] Move FileCheck implementation out of LLVMSupport into its own library"
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   ed89eb3..da0d43d  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to da0d43d90a4f931466ecdd9bc27c47fa45cc6c21.
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!