Use a more reliable way of detecting the notebook
Use a more reliable way of detecting the notebook

With help from @akhmerov on Gitter.

hjanime/VisTrails,minesense/VisTrails,minesense/VisTrails,VisTrails/VisTrails,minesense/VisTrails,VisTrails/VisTrails,minesense/VisTrails,hjanime/VisTrails,hjanime/VisTrails,hjanime/VisTrails,VisTrails/VisTrails,minesense/VisTrails,hjanime/VisTrails,VisTrails/VisTrails,VisTrails/VisTrails