Updated the cmake version (#236)

Co-authored-by: Dmitriy Suponitskiy <dsuponitskiy@dualitytech.com>

CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required (VERSION 3.5.1)
+cmake_minimum_required (VERSION 3.16.3)
 
 project (OpenFHE-Python)