psg-view bug with matplotlib

[gfetterman]

matplotlib versions >2.0.2 reveal a bug in reading .csv label files. Some updates to psg-view code may be required.

[gfetterman]

Some more detail: bark-psg-view starts ok, prompts for files, and displays the sampled datasets without a problem. It leaves the top plot (the ELAN behavioral labels, loaded from a Bark event dataset) empty, however.