[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 719ab73 scudo: Make it thread-safe to set some runtime configuration flags.
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   719ab73..700e632  master     -> origin/master
Auto packing the repository for optimum performance. You may also
run "git gc" manually. See "git help gc" for more information.
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 700e63293eea4a23440f300b1e9125ca2e80c6e9.
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!