Merge pull request #49 from sergiud/cmake-visibility

Fixed warning caused by policy CMP0063 introduced in CMake 3.3
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 1e6ce8d..ecb1355 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -4,6 +4,10 @@
   cmake_policy (SET CMP0042 NEW)
 endif (POLICY CMP0042)
 
+if (POLICY CMP0063)
+  cmake_policy (SET CMP0063 NEW)
+endif (POLICY CMP0063)
+
 project (google-glog)
 
 enable_testing ()