Unknown veg_ values cause issues in albedo decay methods

[micah-prime]

• add test showing that albedo config parses unknown veg_ values as a list of strings rather than a float.
• Update requirements for breaking build. use_2to3 is not allowed with latest setuptools
• Address issue Unknown veg_ values cause issues in albedo decay methods #214

[micah-prime]

@Hedrick-ARS @jomey @scotthavens
Could you give this a look?
This first commit should show where the code breaks, then I will push the fix.

Also, does release-0.9 still build?

[micah-prime]

version 0.21 won't build with the latest setup tools due to use_2to3 being a deprecated option.

[scotthavens]

Why is this package needed and where is it used? The current version removed a lot of requirements that aren't needed.

[jomey]

Don't have enough insights for the 0.9 release.
The code base back then also was tested against Travis and that has since changed.

What is the motivation to have this only changed in an older release?

[micah-prime]

@jomey it should be fixed in the newer release as well. I can take a look at that soon. I just started with the stable version.

[scotthavens]

We ran out of credits on Travis and they won't give us more so we moved to GH actions. This won't build anymore so you'll have to limp this along until a new release can be cut.

Let's discuss this in #214 as I don't see the reason for the fix yet.