Add MS Visual Studio 2015 support

msvc/projects/vc2015/test_threads/test_threads_main.cpp

@@ -0,0 +1,12 @@
+#include "test_threads.h"
+#include <future>
+#include <functional>
+#include <chrono>
+
+using namespace std::chrono_literals;
+
+int main(int argc, char** argv)
+{
+  int rc = test_threads();
+  return rc;
+}