Upstream had several cmake version-related changes like [1] but staying
conservative in this old release for [2].

[1] https://github.com/teeworlds/teeworlds/commit/15dbf346
[2] https://bugs.gentoo.org/957687
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1 +1 @@
-cmake_minimum_required(VERSION 2.8)
+cmake_minimum_required(VERSION 2.8...3.16)