applied black

I ran "black" on the codebase to make gwinc as PEP8 and formatting consistent as it gets -- at least until we remove the egregious 'import *' in the budget codes. I then removed whitespace around '**' operators (the only undesirable thing that black does).

I propose we standardize using black to remove PEP8 frustrations from developers during MR's. I am happy with the consistency of "black" and, while it is beta, it is actively being used by a number of large projects and hosted by the PSF.