Re-introduces unit tests

	modified:   pandora_vision_hole_detector/include/utils/defines.h
	modified:   pandora_vision_hole_detector/src/hole_fusion_node/hole_merger.cpp
	modified:   pandora_vision_hole_detector/src/utils/parameters.cpp
	modified:   pandora_vision_hole_detector/test/unit/hole_fusion_node/hole_merger_test.cpp