jupyter startup script: fallback if sage not installed
jupyter startup script: fallback if sage not installed

DrXyzzy/smc,DrXyzzy/smc,sagemathinc/smc,sagemathinc/smc,tscholl2/smc,sagemathinc/smc,DrXyzzy/smc,tscholl2/smc,DrXyzzy/smc,tscholl2/smc,tscholl2/smc,sagemathinc/smc,tscholl2/smc