Added additional test for uncolored batches in triangle-batch-test.
Added additional test for uncolored batches in triangle-batch-test.

grimfang4/sdl-gpu,ademuri/sdl-gpu,ademuri/sdl-gpu,grimfang4/sdl-gpu,ademuri/sdl-gpu,grimfang4/sdl-gpu,ademuri/sdl-gpu,grimfang4/sdl-gpu