Graticule 0.3.3

• An area named over two columns joins: data.key may be a list such as ["county", "state"], joined as Mohave, AZ. A county column next to a column called state is found without being listed, by join, init (--key county,state names the pair), the spec and the playground, where it also decides the region over a bare state column.
• A CSV with only a header row says so.
• The unit tests run on Windows and macOS as well as Linux on every push.