[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at b5dd2cd [UpdateTestChecks] Don't skip attributes when comparing functions
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   b5dd2cd..bf21ce7  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to bf21ce7b908e16db76f5704714ee83e61a9da95b.
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!