Working on worlds.

It's currently crashing.

tests/CMakeLists.txt

@@ -4,7 +4,7 @@ set(THREADS_PREFER_PTHREAD_FLAG ON)
 find_package(Threads REQUIRED)
 
 set(TESTS_SRC tuple_test.cpp colour_test.cpp canvas_test.cpp matrix_test.cpp transformation_test.cpp ray_test.cpp
-        intersect_test.cpp sphere_test.cpp light_test.cpp material_test.cpp)
+        intersect_test.cpp sphere_test.cpp light_test.cpp material_test.cpp world_test.cpp)
 
 add_executable(testMyRays)
 target_include_directories(testMyRays PUBLIC ${gtest_SOURCE_DIR}/include ${gtest_SOURCE_DIR})