Python 3 for review

[ChristinaB]

Daniella - It looks like you have made a few updates since I forked. I can make those changes manually unless you suggest other steps for pull request. Do you want a different branch?

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This change is 

[aaarendt]

Just a note that I've successfully tested this for ICESat-2 2020 and it's been working great in Python 3. Thanks @deppen8 and @ChristinaB for your work on this. Let me know if I can offer help so this can get merged.

[emiliom]

Any chance this PR could be merged soon? Can I help in some way?

We are getting set to review applications for OceanHackWeek 2020. Applications closed today, and we're on an accelerated track. We haven't made a definitive decision to use Entrofy, but we'd like to. For various reasons (none good), we haven't used it in previous years.
Thanks!

[dhuppenkothen]

I'm really sorry I didn't get to this earlier. Thank you for doing the Python3 conversion. I have two comments:

• Could you perhaps include a summary of the changes somewhere? There are a lot of changes that are formatting only, and it's really hard to sort through what changes beyond formatting were included.
• I think the PR requires a little bit of cleaning up. It looks like perhaps some files were committed accidentally? There are several data files and notebooks for water hack week and geo hack week that were committed as part of the PR that I'm pretty sure shouldn't be there, as well as housekeeping files like ipython notebook checkpoints.

I think the presence of the latter files might raise some privacy concerns? I think I'd recommend updating your fork with the current master of entrofy, cloning a clean copy, make a branch, then copy the files with the relevant changes (e.g. entrofy/core.py), committing those changes, and making a new pull request? Happy to help with that if it turns out to be complicated!

[deppen8]

I can take a run at this tonight since it was my original PR to Christina's fork that kicked things off. I'll make a commit directly to entropy without the Black formatting fun :D

[emiliom]

Thank you @dhuppenkothen! And @deppen8 thanks so much for offering to clean up the original PR! Great to hear from you.

A "direct commit directly to entropy" sounds like a very interesting proposition 😉; maybe more interesting than a commit to entrofy.

[deppen8]

Autocomplete!!! :shakes fist:

To be fair though, most of my commits do increase entropy 😁

[deppen8]

See #63