add scikit-downscale package

[dgergel]

I've been installing this myself for development and testing, but I think we're at a point where it makes sense to have it installed in all of our docker images based on how much usage it's getting!

For context, this is the python package that we are using for our downscaling project - currently building out BCSD functionality and this will be used for building out other methods as well:

https://github.com/jhamman/scikit-downscale

[delgadom]

Is this a dependency of your package? I thought you were working on a fork. Wouldn't installing it make developing it trickier?

[dgergel]

No this is the actual package. I have been working on a fork but thought it would make sense given that in the near-term my implementation mods will start to be part of the actual package too. If we already have it installed, can't you still just pip install -e . if you need to check out a specific remote branch or make dev changes you want to use, and that will override the previously installed version in your environment?