CMake: Bump required version for object libraries
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 896abad..f609c04 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.1)
+cmake_minimum_required(VERSION 3.12)
 project(ninja)
 
 if(MSVC)