Merge pull request #6 from akien-mga/cmake-3.12

CMake: Bump required version to 3.12 for add_compile_definitions

CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.6)
+cmake_minimum_required(VERSION 3.12)
 project(blah)
 
 # C++ version

README.md

@@ -5,7 +5,7 @@ Goal is to be simple and use as few dependencies as possible, to maintain easy b
 **☆ This will likely see breaking changes! Use at your own risk! ☆**
 
 #### building
- - Requires C++17 and CMake
+ - Requires C++17 and CMake 3.12+
  - Platform Backend
 	- [SDL2](https://github.com/NoelFB/blah/blob/master/private/blah/internal/platform_backend_sdl2.cpp) can be enabled in CMake with `SDL2_ENABLED`, and setting `SDL2_INCLUDE_DIRS` and `SDL2_LIBRARIES`
  - Graphics Backend