add more explicit approval test to cpp catch2 version

cpp-catch2/test/gildedrose_catch.cpp

@@ -11,6 +11,7 @@ std::ostream& operator<<(std::ostream& os, const Item& obj)
             << ", quality: " << obj.quality;
 }
 
+// This is a normal unit test using Catch2
 TEST_CASE("UpdateQuality") {
 
     vector<Item> items;
@@ -19,3 +20,13 @@ TEST_CASE("UpdateQuality") {
     app.updateQuality();
     REQUIRE("fixme" == app.items[0].name);
 }
+
+// This is an Approval test using https://github.com/approvals/approvaltests.cpp
+TEST_CASE("UpdateQualityApprovalTest") {
+    vector<Item> items;
+    items.push_back(Item("foo", 0, 0));
+    GildedRose app(items);
+    app.updateQuality();
+    auto item = app.items[0];
+    ApprovalTests::Approvals::verify(item);
+}