2.6.4 is the minimum CMake version, so enforce it (#656)
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8d2b552..5754992 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 2.6.2)
+cmake_minimum_required(VERSION 2.6.4)
 
 project( googletest-distribution )