Adding basic test project files

Added the main source file for running tests in. Added premake4.lua so
you can create a project for "any" platform/target of your choice.
Added gitignore to only add those basic files, ignore everything else.

tests/main.cpp

@@ -0,0 +1,6 @@
+#include "math/Vector3.h"
+
+int main()
+{
+	return 0;
+}