UnitTests: Rename .cpp (it was confusing the debugger)

tests/Engine/Audio/AlgorithmAudioTest.cpp

@@ -0,0 +1,19 @@
+#include <Nazara/Audio/Algorithm.hpp>
+#include <Catch/catch.hpp>
+
+#include <array>
+
+TEST_CASE("MixToMono", "[AUDIO][ALGORITHM]")
+{
+	SECTION("Mix two channels together")
+	{
+		std::array<int, 4> input = { { 1, 3, 5, 3 } };
+		std::array<int, 2> output = { { 0, 0 } };
+
+		// Two channels and two frames !
+		Nz::MixToMono(input.data(), output.data(), 2, 2);
+
+		std::array<int, 2> theoric = { { 2, 4 } }; // It's the mean of the two channels
+		CHECK(output == theoric);
+	}
+}