[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 7e9153e PowerPC: Don't lower SELECT_CC to PPCISD::FSEL on SPE
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   7e9153e..1bd7046  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 1bd7046e4ce0102adef6096a12a289d7f94b8c73.
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!