Minor adjustments
Minor adjustments

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