ENH: make sure cmake has 2.0

CMakeLists.txt

@@ -1,5 +1,5 @@
 PROJECT(CMake)
-CMAKE_MINIMUM_REQUIRED(VERSION 1.8)
+CMAKE_MINIMUM_REQUIRED(VERSION 2.0)
 MARK_AS_ADVANCED(CMAKE_BACKWARDS_COMPATIBILITY)
 
 # The CMake version number.