reorg: test_sptree.py ldng dunderscores to single
reorg: test_sptree.py ldng dunderscores to single

scanny/python-pptx,cchanrhiza/python-pptx,hoopes/python-pptx,AlexMooney/python-pptx,kevingu1003/python-pptx,biggihs/python-pptx