Added an example test case

unit-tests/matrix-tests.cpp

@@ -0,0 +1,12 @@
+#include <catch2/catch_test_macros.hpp>
+
+unsigned int Factorial(unsigned int number) {
+  return number <= 1 ? number : Factorial(number - 1) * number;
+}
+
+TEST_CASE("Factorials are computed", "[factorial]") {
+  REQUIRE(Factorial(1) == 1);
+  REQUIRE(Factorial(2) == 2);
+  REQUIRE(Factorial(3) == 6);
+  REQUIRE(Factorial(10) == 3628800);
+}