`d['url']` points to the url of the repository on github, e.g. `https://github.com/johnmyleswhite/ASCIIPlots.jl`. `/blob/master` is then appended on to it, with the expectation that `d['licfile']` will give us the license filename.  When `d['licfile']` is empty, we get the 404 error.  I'm saying that when `d['licfile']` is empty, we should forgo adding on `/blob/master` at all, so that we just end up going to `https://github.com/johnmyleswhite/ASCIIPlots.jl`.