Fixed reference in PriorityFloodFlowDirector

[BCampforts]

The main change in this PR is to fix a broken reference in the PriorityFloodFlowDirector where the gradients of the hillslopes are being updated. A second fix is to resolve instabilities related to the use of very small H* values when using the "Space_Large_Scale_Eroder". Some other cosmetic changes and added control on location of ylabels of colorbars in imshowhs_grid function. @mcflugen this is a minor change compared to the previous PR, mainly fixing some minor issues.

[mcflugen]

Thanks @BCampforts! Will you please create a news fragment for the changelog?

[mcflugen]

@BCampforts It looks like you removed blank lines from the files you edited. I think, for the most part, we probably want them back—particularly as paragraph separators in the docstrings.

[BCampforts]

Yup, working on it

[BCampforts]

Thanks @BCampforts! Will you please create a news fragment for the changelog?

I added files to the news/ directory, @mcflugen will they be automatically integrated in changelog?

[mcflugen]

I added files to the news/ directory, @mcflugen will they be automatically integrated in changelog?

Yes, they'll be added with the next landlab release. Thanks!

[BCampforts]

There seems to be an issue with the notebooks for macos-latest, 3.8. It has to do with the RichDEM package. Can you have a look at this @mcflugen? Thanks!

[BCampforts]

There seems to be an issue with the notebooks for macos-latest, 3.8. It has to do with the RichDEM package. Can you have a look at this @mcflugen? Thanks!

#1399 solved this. Thanks @mcflugen!

[coveralls]

Coverage increased (+0.02%) to 85.625% when pulling 7216f08 on BCampforts:LS_Runout into 97bb0e2 on landlab:master.

[mcflugen]

@BCampforts you've removed a lot of blank lines from several files. Could you please add them back—particularly in the docstrings where they serve as paragraphs separators? Never mind, I added them back in myself.

[mcflugen]

👍