Change minimum required CMake version to 3.1

The $<TARGET_OBJECTS:objLib> generator expression was introduced in
CMake version 3.1.

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2ea9ba045663e09a1445dcb0dd21df2df54418b2..02405dfeecd416dec0a02ea2d5784acb6062f684 100644 (file)
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,4 +1,4 @@
-cmake_minimum_required (VERSION 2.8 FATAL_ERROR)
+cmake_minimum_required (VERSION 3.1 FATAL_ERROR)
 project (Graphviz)
 
 include(FeatureSummary)