setup.py versioned dependencies and test coverage

[Sean Farley]

Mads Kiilerich writes:

> FYI, Jelmer and I had a little conversation on 
> https://bitbucket.org/conservancy/kallithea/pull-request/15/loosen-some-more-dependencies/diff 
> .
>
> Testing or reviews or better test coverage - or discussion of what we 
> should do - would be appreciated ;-)

I've been running this on my server all day. Let's merge it and improve
the tests later.