Fix mac unittests, specify gtest location explicitly.

CI/ci-mac.sh

@@ -10,6 +10,10 @@ export PATH
 
 OPTIONS=""
 
+OPTIONS="${OPTIONS} -DGTEST_LIBRARY=${HOME}/sw/gtest-1.7.0/lib/libgtest.a"
+OPTIONS="${OPTIONS} -DGTEST_INCLUDE_DIR=${HOME}/sw/gtest-1.7.0/include/"
+OPTIONS="${OPTIONS} -DGTEST_MAIN_LIBRARY=${HOME}/sw/gtest-1.7.0/lib/libgtest_main.a"
+
 if [ "$LANGUAGE" == "C++98" ]; then
   echo "Building with C++98";
 elif [ "$LANGUAGE" == "C++11" ]; then