setup.py: Remove download_url

[msabramo]

IIRC download_url is not so useful anymore because pip much prefers to install from PyPI and will refuse to download from external places without special options.

And that URL was not valid anyway.

[coveralls]

Coverage remained the same at 96.85% when pulling e808bd8 on msabramo:patch-3 into 00a10d4 on noahmorrison:master.

[noahmorrison]

I tried to merge this (along with #7 and #8), but it messed with the git history (conflicts, and three merges on top of each other aren't pretty). I rebased back to the original, which I know is a terrible thing but that's what I get for trying to auto merge. If you feature branch #7 #8 #9 all together, I'll merge them in. Or if you want I'll do it for you.

Thanks for helping me understand pypi a little more though, I really have no idea what I'm doing in terms of that.

[msabramo]

Yikes! Sorry that it caused you so much trouble.

Usually GitHub will tell you there are merge conflicts and won't let you merge. Usually the maintainer (you in this case) would then politely ask the contributor to fix the merge conflicts and rebase.

So usually the burden is on the contributor to make it merge cleanly so that you can just click the button and it works.

[msabramo]

See #12