Make contur-mkhtml able to operate on YODA files outside the current directory
Running e.g. contur-mkhtml 13TeV/0000/*.yoda.gz
results in a Error: failed to copy to directory 'contur-plots'
warning and no output -- for it to work you need to cd
into the run directory and plot the yoda file without any preceding directory path. Obviously not great: we should be able to operate on files regardless of where they are.
Hopefully when fixed, the error message will only be triggered in cases where it makes sense: it's obviously not flagging the real issue in this case. If the path fix is involved, maybe we can fast-track a better warning for "non-pwd" plotting.