Drop Python 2 support about astroplan HOT 3 CLOSED

@cdeil, I think we should support python 2+3 for the first version. I'm probably fine with switching to python 3 only in a later version. The code is already 2 compatible and we could use all the help we can get testing it and getting feedback, so this would definitely argue for keeping 2 support for now, to get the larger user pool. Many observatories are still stuck in 2-land.

Subaru is in the early stages of transition. Some apps like ginga are already 3 compatible, but there is a lot of 2 code left. I think for our use of this astroplan code 3 would be fine, but I'd still argue for 2 support for the reasons I outlined above.

from astroplan.

I'm opposed to dropping 2. A bunch of astronomers that I know work in 2 and don't see a reason to switch to 3 (see astrofrog's post on the state of the migration), and I don't think they'd switch for astroplan (or for anything, frankly).

from astroplan.

There doesn't seem to be support for dropping Python 2 support at this time.
Closing this issue for now ... but I might re-open it and ask again in a year or two...

from astroplan.