Fix "shadow" quartiles delimiters were not perfectly horizontal

[cellomario]

Hi there and thank you for your wonderful tool,

When using the "shadow" mode to visualize the quartile ranges, the highlighted portion of the violin was cut in a non-horizontal fashion due to an off-by-one error. I fixed that.

Old behavior:

New behavior:

[mikelgg93]

I have no Matlab to test it, but the change in the code looks good, and the screenshots too! Perhaps if you have the time you could recreate the figure in the README

[mikelgg93]

This fixes #59

[cellomario]

Will do.

Do you have the script to generate it? It could be included in the repository as an usage example

[mikelgg93]

Unfortunately, I had it locally only, and I no longer have that laptop.

[bastibe]

Wonderful! This looks much better! Thank you for the Pull Request.

Regrettably, I don't have access to Matlab any longer, either, and neither do I have the script for the README plot.

[cellomario]

Done! it's not exactly the same as I was not able to do the weird horizontal offset in the "Italy +1.5" column, and I am not familiar with the colormap you used, so I used the default one, but it's a useful starting point, feel free to modify it when you decide to merge my contributions

[cellomario]

Done! it's not exactly the same as I was not able to do the weird horizontal offset in the "Italy +1.5" column, and I am not familiar with the colormap you used, so I used the default one, but it's a useful starting point, feel free to modify it when you decide to merge my contributions

[bastibe]

Fantastic work, thank you so much!

I'll merge it when you say it's ready!

[cellomario]

Then I'd say it's ready ;)