CMake minimal version update

CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.14)
+cmake_minimum_required(VERSION 3.0)
 project(shell C)
 
 set(CMAKE_C_STANDARD 11)
@@ -6,7 +6,7 @@ set(CMAKE_C_STANDARD 11)
 include_directories(.)
 
 file(STRINGS .git/refs/heads/master BuildRef)
-add_compile_definitions(BUILD_REF="${BuildRef}")
+add_definitions(-DBUILD_REF="${BuildRef}")
 
 add_executable(shell
         esh_deinit.c