Fix bug in constructor make_trail = False
Fix bug in constructor make_trail = False

mwcraig/vpython-jupyter,mwcraig/vpython-jupyter,BruceSherwood/vpython-jupyter,BruceSherwood/vpython-jupyter,mwcraig/vpython-jupyter,BruceSherwood/vpython-jupyter,mwcraig/vpython-jupyter,BruceSherwood/vpython-jupyter