Merge pull request #1340 from boostorg/update

Update Boost Math project version to 1.91.0

Author: mborland

CMakeLists.txt

@@ -5,7 +5,7 @@
 
 cmake_minimum_required(VERSION 3.8...3.16)
 
-project(boost_math VERSION 1.90.0 LANGUAGES CXX)
+project(boost_math VERSION 1.91.0 LANGUAGES CXX)
 
 add_library(boost_math INTERFACE)