[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 89c1e35 [LoopInfo] empty() -> isInnermost(), add isOutermost()
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   89c1e35..7656dd3  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 7656dd33d9326df0b86f08676474dbf8055866b8.
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!