Collapse the test .gitignores into just one section

- Also, it turns out the .dds textures are actually output, not input

.gitignore

@@ -36,14 +36,10 @@ install_manifest.txt
 *.cmake
 # ^ May need to add future .cmake files as exceptions
 
-# Test logs
+# Test output
 Testing/*
-
-# Test input
-test/gtc/*.dds
-
-# Test binaries
 test/*/test-*
+test/gtc/*.dds
 glm/glm_dummy
 
 # Project Files