BUG: Fix death test on linux

Update gtest to latest

CMake/External/External_GTest.cmake

@@ -3,8 +3,8 @@
 #-----------------------------------------------------------------------------
 include(imstkAddExternalProject)
 imstk_add_external_project( GTest
-   URL https://github.com/google/googletest/archive/53495a2a7d6ba7e0691a7f3602e9a5324bba6e45.zip
-   URL_MD5 8349ef674d27b005a43ce3679cb04947
+   URL https://github.com/google/googletest/archive/40dfd4b775a66979ad1bd19321cdfd0feadfea27.zip
+   URL_MD5 222793254ade8010fe6ff000f18c6b15
   CMAKE_CACHE_ARGS
     -DBUILD_GMOCK:BOOL=ON
     -DBUILD_GTEST:BOOL=ON
@@ -14,6 +14,7 @@ imstk_add_external_project( GTest
   RELATIVE_INCLUDE_PATH ""
   #VERBOSE
   )
+
 if(NOT USE_SYSTEM_GTest)
   set(GTest_DIR ${CMAKE_INSTALL_PREFIX}/lib/cmake/GTest)
   #message(STATUS "GTest_DIR : ${GTest_DIR}")

Source/Testing/imstkTestingMain.cpp

@@ -48,5 +48,6 @@ main(int argc, char** argv)
     logger.addFileSink("test", "log");
 
     ::testing::InitGoogleTest(&argc, argv);
+    GTEST_FLAG_SET(death_test_style, "threadsafe");
     return RUN_ALL_TESTS();
 }
\ No newline at end of file