[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 2965e9b [lldb] Hoist --framework argument out of LLDB_TEST_COMMON_ARGS (NFC)
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   2965e9b..6760f7e  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 6760f7ee6f00158c496b8e50d9ddac1f1c631ad7.
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!