using c++11 variadic templates for the templated test cases! relates #137 and #38

this also means less compilers will be usable for doctest 2.0
diff --git a/examples/all_features/header.h b/examples/all_features/header.h
index 116dc50..878b4ae 100644
--- a/examples/all_features/header.h
+++ b/examples/all_features/header.h
@@ -28,7 +28,7 @@
 
 TYPE_TO_STRING(doctest::String);
 
-TEST_CASE_TEMPLATE("template 1", T, doctest::Types<char>) {
+TEST_CASE_TEMPLATE("template 1", T, char) {
     FAIL("");
 }
 
@@ -36,7 +36,7 @@
     FAIL("");
 }
 
-TEST_CASE_TEMPLATE_INSTANTIATE(header_test, doctest::Types<doctest::String>);
+TEST_CASE_TEMPLATE_INSTANTIATE(header_test, doctest::String);
 
 // to silence GCC warnings when inheriting from some class which has no virtual destructor - happens only on gcc 4.7/4.8
 #if DOCTEST_GCC >= DOCTEST_COMPILER(4, 7, 0) && DOCTEST_GCC < DOCTEST_COMPILER(4, 9, 0)