I got it working now. The suggestion to start with an empty ~/.julia/ didn't work, but fortunately I just renamed .julia to .oldjulia and kept everything there. After removing the empty directory, I restored .oldjulia to .julia and then Pkg.update()found a whole slew of new versions of packages. I'm dumfounded, but happy again with jupyter-notebook and the julia kernel.
Another oddity I noticed is that I have a sub-hierarchy of stuff under .julia/, namely .julia/v0.3/ .julia/.julia/v0.3/ There are many duplicate files underneath these two levels. Is this normal? Thanks all for the suggestions!
