fix: upgrade standard, and fix appveyor config so that it works with newest standard

[bcoe]

No description provided.

[maxrimue]

@bcoe What do you think about this part of my comment?

What I was wondering btw., should we maybe drop tests for Default Azure too? Since AppVeyor only lists Windows Server 2012 R2 under available operating systems, I think Default Azure just currently means Windows Server 2012 R2, too, which would mean we run the same tests twice.

I saw we have the same approach in yargs-parser's AppVeyor config, too.

[bcoe]

@maxrimue seems reasonable to also default to Azure.