Add cmin parameter to the Histogram2D class.

[bruno-pannunzio]

This PR proposes the addition of the cmin parameter to the class Histogram2D to be able to modify the cmin parameter of the matplotlib.pyplot.hist2d function called by the data method.

This addition allows to avoid the display of bin with less counts than the cmin value. This will allow to modify the parameter externally, being able to make the background transparent and selecting afterwards the background color by setting the facecolor of the matplotlib axis.

[bruno-pannunzio]

Hi @zoccoler! I opened this PR as discussed. It's a small modification but others can benefit also from this. Please let me know if you want me to modify something and I'll update the PR.

[zoccoler]

Hi @bruno-pannunzio ,

Thanks for contributing here! I just changed the version and will merge now.
Please test it if it is useful for the napari-phasors and let me know, so that I make a new release here.
For the moment, please clone the repo, install the dev version and use the main branch to do the tests.

[bruno-pannunzio]

Thanks @zoccoler! This works perfect with our napari-phasors plugin, after installing the dev version:

[zoccoler]

Awesome!!