[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 7efe07a Traverse-ignore explicit template instantiations
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   7efe07a..d0b8810  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to d0b8810fe4ece12213936605b336777ed5fd06cc.
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!