[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 937bad3 [Utils] Check function attributes in update_test_checks
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   937bad3..cf11050  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to cf1105069648446d58adfb7a6cc590013d6886ba.
CMake Error at CMakeLists.txt:6 (message):
  Your CMake version is 3.7.1.  The minimum version of CMake required to
  build LLVM is now 3.13.4.


-- Configuring incomplete, errors occurred!