Make a PyPI org for attrs

[webknjaz]

I finally got to testing PyPI orgs and I liked them for grouping things. (When Ee announced them, I applied for a Company-type and that still doesn't work so it blocked me for a while).

I think, attrs needs it's own org too. Here's where to apply: https://pypi.org/manage/organizations/ — just make sure to select the Community type.

[hynek]

jftr