Setting cmake_minimum_required to 3.12 for v1.10

Author: sdavtaker

CMakeLists.txt

@@ -2,7 +2,7 @@
 # SPDX-License-Identifier: Apache-2.0.
 #
 
-cmake_minimum_required (VERSION 3.1)
+cmake_minimum_required (VERSION 3.12 FATAL_ERROR)
 if(POLICY CMP0056)
     cmake_policy(SET CMP0056 NEW) # CMP0056: Honor link flags in try_compile() source-file signature. Introduced in 3.2
 endif()
@@ -13,12 +13,6 @@ if (POLICY CMP0077)
     cmake_policy(SET CMP0077 OLD) # CMP0077: option() honors normal variables. Introduced in 3.13
 endif()
 
-# 3.12 or higher is strongly suggested; build settings (target_compile_options/etc...) sometimes do not get propagated properly under certain conditions prior to this version
-# Making this a hard requirement is potentially disruptive to existing customers who aren't affected by the bad behavior though, so just warn for now
-if(CMAKE_VERSION VERSION_LESS 3.12)
-    message(WARNING "Building with CMake 3.12 or higher is strongly suggested; current version is ${CMAKE_VERSION}")
-endif()
-
 get_filename_component(AWS_NATIVE_SDK_ROOT "${CMAKE_CURRENT_SOURCE_DIR}" ABSOLUTE)
 
 # Cmake invocation variables: